diff --git a/crates/iam/src/cache.rs b/crates/iam/src/cache.rs
index 271786c19..a06eaea96 100644
--- a/crates/iam/src/cache.rs
+++ b/crates/iam/src/cache.rs
@@ -15,7 +15,6 @@
 use std::{
     collections::{HashMap, HashSet},
     ops::{Deref, DerefMut},
-    ptr,
     sync::{Arc, Mutex, Weak},
 };
 
@@ -64,21 +63,46 @@ impl Default for CacheState {
 pub struct Cache {
     state: ArcSwap<CacheState>,
     write_lock: Mutex<()>,
+    reload_lock: AsyncMutex<()>,
+    reload_changes: Mutex<Weak<Mutex<ReloadChanges>>>,
     service_account_mutation_lock: AsyncMutex<()>,
-    sts_account_mutation_locks: Arc<StsMutationLockRegistry>,
+    sts_account_mutation_locks: Arc<MutationLockRegistry>,
+    parent_mutation_locks: Arc<MutationLockRegistry>,
 }
 
-struct StsMutationLockRegistry {
-    locks: Mutex<HashMap<String, Weak<AsyncMutex<StsMutationLockState>>>>,
+#[derive(Default)]
+struct MutationLockRegistry {
+    locks: Mutex<HashMap<String, Weak<AsyncMutex<MutationLockState>>>>,
 }
 
-pub(crate) struct StsMutationLockState {
+pub(crate) struct MutationLockState {
     access_key: String,
-    registry: Weak<StsMutationLockRegistry>,
-    lock: Weak<AsyncMutex<StsMutationLockState>>,
+    registry: Weak<MutationLockRegistry>,
+    lock: Weak<AsyncMutex<MutationLockState>>,
 }
 
-impl Drop for StsMutationLockState {
+impl MutationLockRegistry {
+    fn lock_for(self: &Arc<Self>, access_key: &str) -> Arc<AsyncMutex<MutationLockState>> {
+        let mut locks = self.locks.lock().unwrap_or_else(|poisoned| poisoned.into_inner());
+        if let Some(lock) = locks.get(access_key).and_then(Weak::upgrade) {
+            return lock;
+        }
+
+        let registry = Arc::downgrade(self);
+        let access_key_owned = access_key.to_string();
+        let lock = Arc::new_cyclic(|lock| {
+            AsyncMutex::new(MutationLockState {
+                access_key: access_key_owned,
+                registry,
+                lock: lock.clone(),
+            })
+        });
+        locks.insert(access_key.to_string(), Arc::downgrade(&lock));
+        lock
+    }
+}
+
+impl Drop for MutationLockState {
     fn drop(&mut self) {
         let Some(registry) = self.registry.upgrade() else {
             return;
@@ -95,10 +119,52 @@ impl Default for Cache {
         Self {
             state: ArcSwap::new(Arc::new(CacheState::default())),
             write_lock: Mutex::new(()),
+            reload_lock: AsyncMutex::new(()),
+            reload_changes: Mutex::new(Weak::new()),
             service_account_mutation_lock: AsyncMutex::new(()),
-            sts_account_mutation_locks: Arc::new(StsMutationLockRegistry {
-                locks: Mutex::new(HashMap::new()),
-            }),
+            sts_account_mutation_locks: Arc::new(MutationLockRegistry::default()),
+            parent_mutation_locks: Arc::new(MutationLockRegistry::default()),
+        }
+    }
+}
+
+#[derive(Clone, Copy, Hash, PartialEq, Eq)]
+pub(crate) enum CachePartition {
+    PolicyDocs,
+    Users,
+    UserPolicies,
+    StsAccounts,
+    StsPolicies,
+    Groups,
+    UserGroupMemberships,
+    GroupPolicies,
+}
+
+type ReloadChanges = HashMap<CachePartition, HashSet<String>>;
+
+/// A reload journals only keys changed during its own lifetime, including
+/// deletions. Unrelated STS traffic cannot suppress a persisted revocation.
+pub(crate) struct CacheReload<'a> {
+    _guard: tokio::sync::MutexGuard<'a, ()>,
+    changes: Arc<Mutex<ReloadChanges>>,
+}
+
+impl CacheReload<'_> {
+    pub(crate) fn merge_partition<T: Clone>(
+        &self,
+        partition: CachePartition,
+        loaded: &mut CacheEntity<T>,
+        current: &CacheEntity<T>,
+    ) {
+        let changes = self.changes.lock().unwrap_or_else(|poisoned| poisoned.into_inner());
+        if let Some(keys) = changes.get(&partition) {
+            for key in keys {
+                if let Some(value) = current.get(key) {
+                    loaded.insert(key.clone(), value.clone());
+                } else {
+                    loaded.remove(key);
+                }
+            }
         }
     }
 }
@@ -106,31 +172,27 @@ impl Default for Cache {
 pub(crate) type CacheSnapshot = Guard<Arc<CacheState>>;
 
 impl Cache {
+    pub(crate) async fn begin_reload(&self) -> CacheReload<'_> {
+        // Registration and publication both take write_lock before the journal
+        // lock, so no mutation can fall between the reload and its journal.
+        let guard = self.reload_lock.lock().await;
+        let changes = Arc::new(Mutex::new(HashMap::new()));
+        let _write = self.write_lock.lock().unwrap_or_else(|poisoned| poisoned.into_inner());
+        *self.reload_changes.lock().unwrap_or_else(|poisoned| poisoned.into_inner()) = Arc::downgrade(&changes);
+        CacheReload { _guard: guard, changes }
+    }
+
     pub(crate) fn service_account_mutation_lock(&self) -> &AsyncMutex<()> {
         &self.service_account_mutation_lock
     }
 
-    pub(crate) fn sts_account_mutation_lock(&self, access_key: &str) -> Arc<AsyncMutex<StsMutationLockState>> {
-        let mut locks = self
-            .sts_account_mutation_locks
-            .locks
-            .lock()
-            .unwrap_or_else(|poisoned| poisoned.into_inner());
-        if let Some(lock) = locks.get(access_key).and_then(Weak::upgrade) {
-            return lock;
-        }
+    pub(crate) fn sts_account_mutation_lock(&self, access_key: &str) -> Arc<AsyncMutex<MutationLockState>> {
+        self.sts_account_mutation_locks.lock_for(access_key)
+    }
 
-        let registry = Arc::downgrade(&self.sts_account_mutation_locks);
-        let access_key_owned = access_key.to_string();
-        let lock = Arc::new_cyclic(|lock| {
-            AsyncMutex::new(StsMutationLockState {
-                access_key: access_key_owned,
-                registry,
-                lock: lock.clone(),
-            })
-        });
-        locks.insert(access_key.to_string(), Arc::downgrade(&lock));
-        lock
+    /// Orders derived-credential publication with changes to its regular parent.
+    pub(crate) fn parent_mutation_lock(&self, access_key: &str) -> Arc<AsyncMutex<MutationLockState>> {
+        self.parent_mutation_locks.lock_for(access_key)
     }
 
     pub(crate) fn snapshot(&self) -> CacheSnapshot {
@@ -142,7 +204,13 @@ impl Cache {
         let current = self.state.load_full();
         let mut locked = LockedCache {
             state: CacheState::clone(&current),
+            #[cfg(test)]
             current_ptr: Arc::as_ptr(&current),
+            reload_changes: self
+                .reload_changes
+                .lock()
+                .unwrap_or_else(|poisoned| poisoned.into_inner())
+                .upgrade(),
             dirty: false,
         };
         let ret = f(&mut locked);
@@ -215,7 +283,9 @@ impl Cache {
 
 pub(crate) struct LockedCache {
     state: CacheState,
+    #[cfg(test)]
     current_ptr: *const CacheState,
+    reload_changes: Option<Arc<Mutex<ReloadChanges>>>,
     dirty: bool,
 }
 
@@ -224,11 +294,19 @@ impl LockedCache {
         &self.state
     }
 
+    #[cfg(test)]
     pub(crate) fn matches_snapshot(&self, snapshot: &CacheSnapshot) -> bool {
-        ptr::eq(self.current_ptr, Arc::as_ptr(snapshot))
+        std::ptr::eq(self.current_ptr, Arc::as_ptr(snapshot))
     }
 
-    fn exec<T: Clone>(target: &mut Arc<CacheEntity<T>>, t: OffsetDateTime, mut op: impl FnMut(&mut CacheEntity<T>)) -> bool {
+    fn exec<T: Clone>(
+        target: &mut Arc<CacheEntity<T>>,
+        t: OffsetDateTime,
+        changes: Option<&Arc<Mutex<ReloadChanges>>>,
+        partition: CachePartition,
+        key: &str,
+        mut op: impl FnMut(&mut CacheEntity<T>),
+    ) -> bool {
         if target.load_time >= t {
             return false;
         }
@@ -236,6 +314,14 @@ impl LockedCache {
         let mut new = CacheEntity::clone(target);
         op(&mut new);
         *target = Arc::new(new);
+        if let Some(changes) = changes {
+            changes
+                .lock()
+                .unwrap_or_else(|poisoned| poisoned.into_inner())
+                .entry(partition)
+                .or_default()
+                .insert(key.to_string());
+        }
         true
     }
 
@@ -244,139 +330,315 @@ impl LockedCache {
     }
 
     pub(crate) fn replace_policy_docs(&mut self, value: CacheEntity<PolicyDoc>) {
+        if let Some(changes) = &self.reload_changes {
+            changes
+                .lock()
+                .unwrap_or_else(|poisoned| poisoned.into_inner())
+                .entry(CachePartition::PolicyDocs)
+                .or_default()
+                .extend(self.state.policy_docs.keys().chain(value.keys()).cloned());
+        }
         self.state.policy_docs = Self::replaced(value);
         self.dirty = true;
     }
 
     pub(crate) fn replace_users(&mut self, value: CacheEntity<UserIdentity>) {
+        if let Some(changes) = &self.reload_changes {
+            changes
+                .lock()
+                .unwrap_or_else(|poisoned| poisoned.into_inner())
+                .entry(CachePartition::Users)
+                .or_default()
+                .extend(self.state.users.keys().chain(value.keys()).cloned());
+        }
         self.state.users = Self::replaced(value);
         self.dirty = true;
     }
 
     pub(crate) fn replace_user_policies(&mut self, value: CacheEntity<MappedPolicy>) {
+        if let Some(changes) = &self.reload_changes {
+            changes
+                .lock()
+                .unwrap_or_else(|poisoned| poisoned.into_inner())
+                .entry(CachePartition::UserPolicies)
+                .or_default()
+                .extend(self.state.user_policies.keys().chain(value.keys()).cloned());
+        }
         self.state.user_policies = Self::replaced(value);
         self.dirty = true;
     }
 
     pub(crate) fn replace_sts_accounts(&mut self, value: CacheEntity<UserIdentity>) {
+        if let Some(changes) = &self.reload_changes {
+            changes
+                .lock()
+                .unwrap_or_else(|poisoned| poisoned.into_inner())
+                .entry(CachePartition::StsAccounts)
+                .or_default()
+                .extend(self.state.sts_accounts.keys().chain(value.keys()).cloned());
+        }
         self.state.sts_accounts = Self::replaced(value);
         self.dirty = true;
     }
 
     pub(crate) fn replace_sts_policies(&mut self, value: CacheEntity<MappedPolicy>) {
+        if let Some(changes) = &self.reload_changes {
+            changes
+                .lock()
+                .unwrap_or_else(|poisoned| poisoned.into_inner())
+                .entry(CachePartition::StsPolicies)
+                .or_default()
+                .extend(self.state.sts_policies.keys().chain(value.keys()).cloned());
+        }
         self.state.sts_policies = Self::replaced(value);
         self.dirty = true;
     }
 
     pub(crate) fn replace_groups(&mut self, value: CacheEntity<GroupInfo>) {
+        if let Some(changes) = &self.reload_changes {
+            changes
+                .lock()
+                .unwrap_or_else(|poisoned| poisoned.into_inner())
+                .entry(CachePartition::Groups)
+                .or_default()
+                .extend(self.state.groups.keys().chain(value.keys()).cloned());
+        }
         self.state.groups = Self::replaced(value);
         self.dirty = true;
     }
 
     pub(crate) fn replace_group_policies(&mut self, value: CacheEntity<MappedPolicy>) {
+        if let Some(changes) = &self.reload_changes {
+            changes
+                .lock()
+                .unwrap_or_else(|poisoned| poisoned.into_inner())
+                .entry(CachePartition::GroupPolicies)
+                .or_default()
+                .extend(self.state.group_policies.keys().chain(value.keys()).cloned());
+        }
         self.state.group_policies = Self::replaced(value);
         self.dirty = true;
     }
 
     pub(crate) fn replace_user_group_memberships(&mut self, value: CacheEntity<HashSet<String>>) {
+        if let Some(changes) = &self.reload_changes {
+            changes
+                .lock()
+                .unwrap_or_else(|poisoned| poisoned.into_inner())
+                .entry(CachePartition::UserGroupMemberships)
+                .or_default()
+                .extend(self.state.user_group_memberships.keys().chain(value.keys()).cloned());
+        }
         self.state.user_group_memberships = Self::replaced(value);
         self.dirty = true;
     }
 
     pub(crate) fn add_or_update_policy_doc(&mut self, key: &str, value: &PolicyDoc, t: OffsetDateTime) {
-        self.dirty |= Self::exec(&mut self.state.policy_docs, t, |map| {
-            map.insert(key.to_string(), value.clone());
-        });
+        self.dirty |= Self::exec(
+            &mut self.state.policy_docs,
+            t,
+            self.reload_changes.as_ref(),
+            CachePartition::PolicyDocs,
+            key,
+            |map| {
+                map.insert(key.to_string(), value.clone());
+            },
+        );
     }
 
     pub(crate) fn add_or_update_user(&mut self, key: &str, value: &UserIdentity, t: OffsetDateTime) {
-        self.dirty |= Self::exec(&mut self.state.users, t, |map| {
-            map.insert(key.to_string(), value.clone());
-        });
+        self.dirty |= Self::exec(
+            &mut self.state.users,
+            t,
+            self.reload_changes.as_ref(),
+            CachePartition::Users,
+            key,
+            |map| {
+                map.insert(key.to_string(), value.clone());
+            },
+        );
     }
 
     pub(crate) fn add_or_update_user_policy(&mut self, key: &str, value: &MappedPolicy, t: OffsetDateTime) {
-        self.dirty |= Self::exec(&mut self.state.user_policies, t, |map| {
-            map.insert(key.to_string(), value.clone());
-        });
+        self.dirty |= Self::exec(
+            &mut self.state.user_policies,
+            t,
+            self.reload_changes.as_ref(),
+            CachePartition::UserPolicies,
+            key,
+            |map| {
+                map.insert(key.to_string(), value.clone());
+            },
+        );
     }
 
     pub(crate) fn add_or_update_sts_account(&mut self, key: &str, value: &UserIdentity, t: OffsetDateTime) {
-        self.dirty |= Self::exec(&mut self.state.sts_accounts, t, |map| {
-            map.insert(key.to_string(), value.clone());
-        });
+        self.dirty |= Self::exec(
+            &mut self.state.sts_accounts,
+            t,
+            self.reload_changes.as_ref(),
+            CachePartition::StsAccounts,
+            key,
+            |map| {
+                map.insert(key.to_string(), value.clone());
+            },
+        );
     }
 
     pub(crate) fn add_or_update_sts_policy(&mut self, key: &str, value: &MappedPolicy, t: OffsetDateTime) {
-        self.dirty |= Self::exec(&mut self.state.sts_policies, t, |map| {
-            map.insert(key.to_string(), value.clone());
-        });
+        self.dirty |= Self::exec(
+            &mut self.state.sts_policies,
+            t,
+            self.reload_changes.as_ref(),
+            CachePartition::StsPolicies,
+            key,
+            |map| {
+                map.insert(key.to_string(), value.clone());
+            },
+        );
     }
 
     pub(crate) fn add_or_update_group(&mut self, key: &str, value: &GroupInfo, t: OffsetDateTime) {
-        self.dirty |= Self::exec(&mut self.state.groups, t, |map| {
-            map.insert(key.to_string(), value.clone());
-        });
+        self.dirty |= Self::exec(
+            &mut self.state.groups,
+            t,
+            self.reload_changes.as_ref(),
+            CachePartition::Groups,
+            key,
+            |map| {
+                map.insert(key.to_string(), value.clone());
+            },
+        );
     }
 
     pub(crate) fn add_or_update_user_group_membership(&mut self, key: &str, value: &HashSet<String>, t: OffsetDateTime) {
-        self.dirty |= Self::exec(&mut self.state.user_group_memberships, t, |map| {
-            map.insert(key.to_string(), value.clone());
-        });
+        self.dirty |= Self::exec(
+            &mut self.state.user_group_memberships,
+            t,
+            self.reload_changes.as_ref(),
+            CachePartition::UserGroupMemberships,
+            key,
+            |map| {
+                map.insert(key.to_string(), value.clone());
+            },
+        );
     }
 
     pub(crate) fn add_or_update_group_policy(&mut self, key: &str, value: &MappedPolicy, t: OffsetDateTime) {
-        self.dirty |= Self::exec(&mut self.state.group_policies, t, |map| {
-            map.insert(key.to_string(), value.clone());
-        });
+        self.dirty |= Self::exec(
+            &mut self.state.group_policies,
+            t,
+            self.reload_changes.as_ref(),
+            CachePartition::GroupPolicies,
+            key,
+            |map| {
+                map.insert(key.to_string(), value.clone());
+            },
+        );
     }
 
     pub(crate) fn delete_policy_doc(&mut self, key: &str, t: OffsetDateTime) {
-        self.dirty |= Self::exec(&mut self.state.policy_docs, t, |map| {
-            map.remove(key);
-        });
+        self.dirty |= Self::exec(
+            &mut self.state.policy_docs,
+            t,
+            self.reload_changes.as_ref(),
+            CachePartition::PolicyDocs,
+            key,
+            |map| {
+                map.remove(key);
+            },
+        );
     }
 
     pub(crate) fn delete_user(&mut self, key: &str, t: OffsetDateTime) {
-        self.dirty |= Self::exec(&mut self.state.users, t, |map| {
-            map.remove(key);
-        });
+        self.dirty |= Self::exec(
+            &mut self.state.users,
+            t,
+            self.reload_changes.as_ref(),
+            CachePartition::Users,
+            key,
+            |map| {
+                map.remove(key);
+            },
+        );
     }
 
     pub(crate) fn delete_user_policy(&mut self, key: &str, t: OffsetDateTime) {
-        self.dirty |= Self::exec(&mut self.state.user_policies, t, |map| {
-            map.remove(key);
-        });
+        self.dirty |= Self::exec(
+            &mut self.state.user_policies,
+            t,
+            self.reload_changes.as_ref(),
+            CachePartition::UserPolicies,
+            key,
+            |map| {
+                map.remove(key);
+            },
+        );
     }
 
     pub(crate) fn delete_user_group_membership(&mut self, key: &str, t: OffsetDateTime) {
-        self.dirty |= Self::exec(&mut self.state.user_group_memberships, t, |map| {
-            map.remove(key);
-        });
+        self.dirty |= Self::exec(
+            &mut self.state.user_group_memberships,
+            t,
+            self.reload_changes.as_ref(),
+            CachePartition::UserGroupMemberships,
+            key,
+            |map| {
+                map.remove(key);
+            },
+        );
     }
 
     pub(crate) fn delete_sts_account(&mut self, key: &str, t: OffsetDateTime) {
-        self.dirty |= Self::exec(&mut self.state.sts_accounts, t, |map| {
-            map.remove(key);
-        });
+        self.dirty |= Self::exec(
+            &mut self.state.sts_accounts,
+            t,
+            self.reload_changes.as_ref(),
+            CachePartition::StsAccounts,
+            key,
+            |map| {
+                map.remove(key);
+            },
+        );
     }
 
     pub(crate) fn delete_sts_policy(&mut self, key: &str, t: OffsetDateTime) {
-        self.dirty |= Self::exec(&mut self.state.sts_policies, t, |map| {
-            map.remove(key);
-        });
+        self.dirty |= Self::exec(
+            &mut self.state.sts_policies,
+            t,
+            self.reload_changes.as_ref(),
+            CachePartition::StsPolicies,
+            key,
+            |map| {
+                map.remove(key);
+            },
+        );
     }
 
     pub(crate) fn delete_group(&mut self, key: &str, t: OffsetDateTime) {
-        self.dirty |= Self::exec(&mut self.state.groups, t, |map| {
-            map.remove(key);
-        });
+        self.dirty |= Self::exec(
+            &mut self.state.groups,
+            t,
+            self.reload_changes.as_ref(),
+            CachePartition::Groups,
+            key,
+            |map| {
+                map.remove(key);
+            },
+        );
     }
 
     pub(crate) fn delete_group_policy(&mut self, key: &str, t: OffsetDateTime) {
-        self.dirty |= Self::exec(&mut self.state.group_policies, t, |map| {
-            map.remove(key);
-        });
+        self.dirty |= Self::exec(
+            &mut self.state.group_policies,
+            t,
+            self.reload_changes.as_ref(),
+            CachePartition::GroupPolicies,
+            key,
+            |map| {
+                map.remove(key);
+            },
+        );
     }
 
     pub(crate) fn build_user_group_memberships(&mut self) {
@@ -494,6 +756,50 @@ mod tests {
     use crate::cache::Cache;
     use crate::store::MappedPolicy;
 
+    #[tokio::test]
+    async fn reload_journal_preserves_same_key_mutations_and_expires_on_cancellation() {
+        use super::{CacheEntity, CachePartition};
+        let cache = Cache::default();
+        let stale = UserIdentity {
+            version: 1,
+            ..Default::default()
+        };
+        let current = UserIdentity {
+            version: 2,
+            ..Default::default()
+        };
+        let reload = cache.begin_reload().await;
+        cache.add_or_update_user("updated", &current, OffsetDateTime::now_utc());
+        cache.add_or_update_user("removed", &current, OffsetDateTime::now_utc());
+        cache.delete_user("removed", OffsetDateTime::now_utc());
+        // Even an absent key's deletion is recorded: storage may have returned
+        // an entry created and deleted entirely during the reload's reads.
+        cache.delete_user("absent", OffsetDateTime::now_utc());
+        let mut loaded = CacheEntity::new(std::collections::HashMap::from([
+            ("updated".to_string(), stale.clone()),
+            ("removed".to_string(), stale.clone()),
+            ("absent".to_string(), stale.clone()),
+            ("disk-only".to_string(), stale),
+        ]));
+        cache.with_write_lock(|locked| {
+            reload.merge_partition(CachePartition::Users, &mut loaded, &locked.state().users);
+            locked.replace_users(loaded);
+        });
+        let snapshot = cache.snapshot();
+        assert_eq!(snapshot.users["updated"].version, 2);
+        assert!(!snapshot.users.contains_key("removed"));
+        assert!(!snapshot.users.contains_key("absent"));
+        assert!(snapshot.users.contains_key("disk-only"));
+        drop(reload);
+        assert!(cache.reload_changes.lock().expect("journal lock").upgrade().is_none());
+        let cancelled = cache.begin_reload().await;
+        cache.delete_user("disk-only", OffsetDateTime::now_utc());
+        drop(cancelled);
+        assert!(cache.reload_changes.lock().expect("journal lock").upgrade().is_none());
+        let next = cache.begin_reload().await;
+        assert!(next.changes.lock().expect("new journal").is_empty());
+    }
+
     #[test]
     fn sts_mutation_locks_are_keyed_and_prune_unused_entries() {
         let cache = Cache::default();
diff --git a/crates/iam/src/federation/mapper.rs b/crates/iam/src/federation/mapper.rs
index 6680a2471..bcd689e22 100644
--- a/crates/iam/src/federation/mapper.rs
+++ b/crates/iam/src/federation/mapper.rs
@@ -16,6 +16,7 @@ use super::{FederatedClaims, VerifiedFederatedIdentity};
 use crate::{EVENT_OIDC_DIAGNOSTICS, LOG_COMPONENT_IAM, LOG_SUBSYSTEM_OIDC};
 use rustfs_policy::policy::{ClaimLookup, get_claim_case_insensitive};
 use rustfs_utils::HashAlgorithm;
+use serde_json::Value;
 use std::{collections::HashMap, sync::Arc};
 use tracing::debug;
 
@@ -66,6 +67,15 @@ impl FederatedAuthorization {
         &self.provider_id
     }
 
+    /// Issuer from the verified upstream identity.
+    pub fn issuer(&self) -> Option<&str> {
+        self.claims
+            .raw
+            .get("iss")
+            .and_then(Value::as_str)
+            .filter(|issuer| !issuer.is_empty())
+    }
+
     pub fn subject(&self) -> &str {
         &self.claims.sub
     }
diff --git a/crates/iam/src/manager.rs b/crates/iam/src/manager.rs
index c97c7e49d..1a32e45db 100644
--- a/crates/iam/src/manager.rs
+++ b/crates/iam/src/manager.rs
@@ -415,6 +415,16 @@ where
 
         self.api.save_iam_config(IAMFormat::new_version_1(), path).await
     }
+    /// Current built-in IAM group membership, independent of credential snapshots.
+    pub fn user_group_memberships(&self, name: &str) -> Vec<String> {
+        self.cache
+            .snapshot()
+            .user_group_memberships
+            .get(name)
+            .map(|groups| groups.iter().cloned().collect())
+            .unwrap_or_default()
+    }
+
     pub async fn get_user(&self, access_key: &str) -> Option<UserIdentity> {
         let cache = self.cache.snapshot();
         cache
@@ -1005,6 +1015,17 @@ where
     }
 
     pub async fn sts_policy_db_get(&self, name: &str, groups: &Option<Vec<String>>) -> Result<Vec<String>> {
+        self.sts_policy_db_get_with_identity_mapping(name, groups)
+            .await
+            .map(|(policies, _)| policies)
+    }
+
+    /// Resolve STS policies and whether that same lookup found a nonempty identity mapping.
+    pub async fn sts_policy_db_get_with_identity_mapping(
+        &self,
+        name: &str,
+        groups: &Option<Vec<String>>,
+    ) -> Result<(Vec<String>, bool)> {
         if name.is_empty() {
             return Err(Error::InvalidArgument);
         }
@@ -1031,7 +1052,10 @@ where
             }
         };
 
-        self.policy_db_get_with_groups(mapped_policy.to_slice(), groups).await
+        let direct_policies = mapped_policy.to_slice();
+        let has_identity_mapping = !direct_policies.is_empty();
+        let policies = self.policy_db_get_with_groups(direct_policies, groups).await?;
+        Ok((policies, has_identity_mapping))
     }
 
     async fn policy_db_get_with_groups(&self, mut policies: Vec<String>, groups: &Option<Vec<String>>) -> Result<Vec<String>> {
@@ -1158,7 +1182,7 @@ where
         if let Some(groups) = u.credentials.groups.as_ref() {
             for group in groups.iter() {
                 if groups_cache.get(group).filter(|v| v.status == STATUS_DISABLED).is_some() {
-                    return Ok((Vec::new(), OffsetDateTime::now_utc()));
+                    continue;
                 }
 
                 let mp = match group_policies.get(group) {
@@ -1189,7 +1213,7 @@ where
 
         for group in user_group_memberships.get(name).cloned().unwrap_or_default().iter() {
             if groups_cache.get(group).filter(|v| v.status == STATUS_DISABLED).is_some() {
-                return Ok((Vec::new(), OffsetDateTime::now_utc()));
+                continue;
             }
 
             let mp = match group_policies.get(group) {
@@ -1486,7 +1510,27 @@ where
         args: &AddOrUpdateUserReq,
         updated_at: OffsetDateTime,
     ) -> Result<OffsetDateTime> {
+        self.add_user_at_with_secret_change(access_key, args, updated_at)
+            .await
+            .map(|(updated_at, _, _guard)| updated_at)
+    }
+
+    /// Return whether this write replaced a different regular-user secret.
+    pub(crate) async fn add_user_at_with_secret_change(
+        &self,
+        access_key: &str,
+        args: &AddOrUpdateUserReq,
+        updated_at: OffsetDateTime,
+    ) -> Result<(OffsetDateTime, bool, tokio::sync::OwnedMutexGuard<crate::cache::MutationLockState>)> {
+        let parent_lock = self.cache.parent_mutation_lock(access_key);
+        let parent_guard = parent_lock.lock_owned().await;
+        let _service_guard = self.cache.service_account_mutation_lock().lock().await;
+        let sts_lock = self.cache.sts_account_mutation_lock(access_key);
+        let _sts_guard = sts_lock.lock().await;
         let cache = self.cache.snapshot();
+        if cache.sts_accounts.contains_key(access_key) {
+            return Err(Error::AccessKeyAlreadyExists);
+        }
         let users = Arc::clone(&cache.users);
         if let Some(x) = users.get(access_key) {
             debug!(
@@ -1496,10 +1540,13 @@ where
                 state = "existing",
                 "Updating existing IAM user"
             );
-            if x.credentials.is_temp() {
+            if x.credentials.is_temp() || x.credentials.is_service_account() {
                 return Err(Error::AccessKeyAlreadyExists);
             }
         }
+        let secret_changed = users
+            .get(access_key)
+            .is_some_and(|user| user.credentials.secret_key != args.secret_key);
         drop(cache);
         drop(users);
 
@@ -1523,7 +1570,7 @@ where
 
         self.update_user_with_claims(access_key, user_entry)?;
 
-        Ok(updated_at)
+        Ok((updated_at, secret_changed, parent_guard))
     }
 
     pub async fn delete_user(&self, access_key: &str, utype: UserType) -> Result<()> {
@@ -1540,12 +1587,17 @@ where
             return Err(Error::InvalidArgument);
         }
 
+        let parent_lock = (utype == UserType::Reg).then(|| self.cache.parent_mutation_lock(access_key));
+        let _parent_guard = match &parent_lock {
+            Some(lock) => Some(lock.lock().await),
+            None => None,
+        };
         let sts_mutation_lock = (utype == UserType::Sts).then(|| self.cache.sts_account_mutation_lock(access_key));
         let _sts_mutation_guard = match &sts_mutation_lock {
             Some(lock) => Some(lock.lock().await),
             None => None,
         };
-        let _service_account_guard = if utype == UserType::Svc {
+        let _service_account_guard = if matches!(utype, UserType::Svc | UserType::Reg) {
             Some(self.cache.service_account_mutation_lock().lock().await)
         } else {
             None
@@ -1640,17 +1692,46 @@ where
     }
 
     pub async fn update_user_secret_key(&self, access_key: &str, secret_key: &str) -> Result<(OffsetDateTime, AccountStatus)> {
+        self.update_user_secret_key_with_guard(access_key, secret_key, None)
+            .await
+            .map(|(updated_at, status, _guard)| (updated_at, status))
+    }
+
+    pub(crate) async fn update_user_secret_key_with_guard(
+        &self,
+        access_key: &str,
+        secret_key: &str,
+        expected_secret: Option<&str>,
+    ) -> Result<(
+        OffsetDateTime,
+        AccountStatus,
+        tokio::sync::OwnedMutexGuard<crate::cache::MutationLockState>,
+    )> {
         if access_key.is_empty() || secret_key.is_empty() {
             return Err(Error::InvalidArgument);
         }
 
+        let parent_lock = self.cache.parent_mutation_lock(access_key);
+        let parent_guard = parent_lock.lock_owned().await;
         let cache = self.cache.snapshot();
         let users = Arc::clone(&cache.users);
         let u = match users.get(access_key) {
             Some(u) => u,
+            None if expected_secret.is_some() => return Err(Error::IAMActionNotAllowed),
             None => return Err(Error::NoSuchUser(access_key.to_string())),
         };
 
+        if let Some(expected) = expected_secret {
+            use subtle::ConstantTimeEq as _;
+            if !u.credentials.is_valid()
+                || u.credentials.is_temp()
+                || u.credentials.is_service_account()
+                || !bool::from(u.credentials.secret_key.as_bytes().ct_eq(expected.as_bytes()))
+            {
+                return Err(Error::IAMActionNotAllowed);
+            }
+        }
+
         let mut cred = u.credentials.clone();
         cred.secret_key = secret_key.to_string();
 
@@ -1672,7 +1753,7 @@ where
             .await?;
 
         self.update_user_with_claims(access_key, u)?;
-        Ok((updated_at, status))
+        Ok((updated_at, status, parent_guard))
     }
 
     /// Add SSH public key for a user (for SFTP authentication)
@@ -1681,6 +1762,8 @@ where
             return Err(Error::InvalidArgument);
         }
 
+        let parent_lock = self.cache.parent_mutation_lock(access_key);
+        let _parent_guard = parent_lock.lock().await;
         let cache = self.cache.snapshot();
         let users = Arc::clone(&cache.users);
         let u = match users.get(access_key) {
@@ -1720,6 +1803,8 @@ where
             return Err(Error::InvalidArgument);
         }
 
+        let parent_lock = self.cache.parent_mutation_lock(access_key);
+        let _parent_guard = parent_lock.lock().await;
         let cache = self.cache.snapshot();
         let users = Arc::clone(&cache.users);
         let u = match users.get(access_key) {
@@ -2238,6 +2323,11 @@ where
         Ok(())
     }
     pub async fn user_notification_handler(&self, name: &str, user_type: UserType) -> Result<()> {
+        let parent_lock = (user_type == UserType::Reg).then(|| self.cache.parent_mutation_lock(name));
+        let _parent_guard = match &parent_lock {
+            Some(lock) => Some(lock.lock().await),
+            None => None,
+        };
         let sts_mutation_lock = (user_type == UserType::Sts).then(|| self.cache.sts_account_mutation_lock(name));
         let _sts_mutation_guard = match &sts_mutation_lock {
             Some(lock) => Some(lock.lock().await),
@@ -2985,6 +3075,58 @@ mod tests {
         }
     }
 
+    #[tokio::test]
+    async fn disabled_group_preserves_direct_and_other_group_policies() {
+        for credential_groups in [false, true] {
+            let iam = build_test_iam_cache(FailingInitialLoadStore);
+            let groups = vec!["disabled".to_string(), "enabled".to_string()];
+            let user = UserIdentity::new(Credentials {
+                access_key: "alice".to_string(),
+                secret_key: "alice-secret".to_string(),
+                status: STATUS_ENABLED.to_string(),
+                groups: credential_groups.then(|| groups.clone()),
+                ..Default::default()
+            });
+            let now = OffsetDateTime::now_utc();
+            iam.cache.add_or_update_user("alice", &user, now);
+            iam.cache
+                .add_or_update_user_policy("alice", &MappedPolicy::new("direct-deny"), now);
+            if !credential_groups {
+                iam.cache
+                    .add_or_update_user_group_membership("alice", &groups.iter().cloned().collect(), now);
+            }
+            for (group, status, policy) in [
+                ("disabled", STATUS_DISABLED, "disabled-grant"),
+                ("enabled", STATUS_ENABLED, "other-group-deny"),
+            ] {
+                iam.cache.add_or_update_group(
+                    group,
+                    &GroupInfo {
+                        status: status.to_string(),
+                        members: vec!["alice".to_string()],
+                        ..Default::default()
+                    },
+                    now,
+                );
+                iam.cache.add_or_update_group_policy(group, &MappedPolicy::new(policy), now);
+            }
+            let policies: HashSet<_> = iam
+                .policy_db_get("alice", &None)
+                .await
+                .expect("user policy lookup")
+                .into_iter()
+                .collect();
+            assert_eq!(policies, HashSet::from(["direct-deny".to_string(), "other-group-deny".to_string()]));
+            assert!(
+                iam.policy_db_get_internal("disabled", true, false)
+                    .await
+                    .expect("disabled group lookup")
+                    .0
+                    .is_empty()
+            );
+        }
+    }
+
     #[tokio::test]
     async fn sts_policy_lookup_ignores_colliding_regular_user_mapping() {
         let iam = build_test_iam_cache(FailingInitialLoadStore);
diff --git a/crates/iam/src/oidc/provider.rs b/crates/iam/src/oidc/provider.rs
index 4ab398762..b9f7e63a1 100644
--- a/crates/iam/src/oidc/provider.rs
+++ b/crates/iam/src/oidc/provider.rs
@@ -18,18 +18,19 @@ use super::{
 use crate::{EVENT_OIDC_DIAGNOSTICS, LOG_COMPONENT_IAM, LOG_SUBSYSTEM_OIDC};
 use openidconnect::core::{CoreIdToken, CoreIdTokenClaims, CoreIdTokenVerifier, CoreJsonWebKeySet, CoreJwsSigningAlgorithm};
 use openidconnect::{
-    AsyncHttpClient, ClaimsVerificationError, ClientId, ClientSecret, DiscoveryError, IssuerUrl, JsonWebKeySetUrl, NonceVerifier,
+    AsyncHttpClient, ClaimsVerificationError, ClientId, DiscoveryError, IssuerUrl, JsonWebKeySetUrl, NonceVerifier,
     ProviderMetadataWithLogout, SignatureVerificationError, TokenUrl,
 };
 use serde::Deserialize;
 use std::collections::HashMap;
-use std::sync::RwLock;
+use std::sync::{Arc, Mutex, RwLock};
 use std::time::{Duration as StdDuration, Instant};
 use tokio::time::sleep;
 use tracing::{debug, warn};
 use url::Url;
 
 pub(super) const OIDC_JWKS_REFRESH_INTERVAL: StdDuration = StdDuration::from_secs(24 * 60 * 60);
+const OIDC_JWKS_REFRESH_COOLDOWN: StdDuration = StdDuration::from_secs(60);
 pub(super) const OIDC_DISCOVERY_TRANSPORT_RETRIES: usize = 3;
 pub(super) const OIDC_DISCOVERY_TRANSPORT_RETRY_DELAY: StdDuration = StdDuration::from_millis(50);
 pub(super) const OIDC_JWKS_BLOCKED_BY_OUTBOUND_POLICY: &str = "JWKS request blocked by outbound policy";
@@ -97,9 +98,14 @@ pub(super) struct ProviderState {
     pub(super) discovered_at: Instant,
 }
 
+type RefreshAttempt = Option<(Instant, Result<ProviderState, String>)>;
+type ProviderRefreshLock = Arc<tokio::sync::Mutex<RefreshAttempt>>;
+
+#[derive(Clone)]
 pub(super) struct ProviderRuntime {
-    states: RwLock<HashMap<String, ProviderState>>,
-    http_client: ReqwestHttpClient,
+    states: Arc<RwLock<HashMap<String, ProviderState>>>,
+    http_client: Arc<ReqwestHttpClient>,
+    refreshes: Arc<Mutex<HashMap<String, ProviderRefreshLock>>>,
 }
 
 // Workload issuers do not implement the browser authorization flow. Keep their
@@ -200,16 +206,25 @@ impl DiscoveredProviderMetadata {
 
     pub(super) fn verifier(&self, config: &OidcProviderConfig) -> CoreIdTokenVerifier<'static> {
         let client_id = ClientId::new(config.client_id.clone());
-        let secret = config.client_secret.as_ref().map(|secret| ClientSecret::new(secret.clone()));
         let (issuer, jwks, algorithms) = match self {
             Self::Console(metadata) => (metadata.issuer(), metadata.jwks(), metadata.id_token_signing_alg_values_supported()),
             Self::Workload(metadata) => (&metadata.issuer, &metadata.jwks, &metadata.id_token_signing_alg_values_supported),
         };
-        let verifier = match secret {
-            Some(secret) => CoreIdTokenVerifier::new_confidential_client(client_id, secret, issuer.clone(), jwks.clone()),
-            None => CoreIdTokenVerifier::new_public_client(client_id, issuer.clone(), jwks.clone()),
-        };
-        verifier.set_allowed_algs(algorithms.clone())
+        // Caller-supplied tokens must prove possession of the issuer's signing
+        // key. A client secret is shared with clients and cannot provide that proof.
+        let algorithms = algorithms
+            .iter()
+            .filter(|algorithm| {
+                !matches!(
+                    algorithm,
+                    CoreJwsSigningAlgorithm::HmacSha256
+                        | CoreJwsSigningAlgorithm::HmacSha384
+                        | CoreJwsSigningAlgorithm::HmacSha512
+                )
+            })
+            .cloned()
+            .collect::<Vec<_>>();
+        CoreIdTokenVerifier::new_public_client(client_id, issuer.clone(), jwks.clone()).set_allowed_algs(algorithms)
     }
 }
 
@@ -273,8 +288,9 @@ impl ProviderState {
 impl ProviderRuntime {
     pub(super) fn new(http_client: ReqwestHttpClient, states: HashMap<String, ProviderState>) -> Self {
         Self {
-            states: RwLock::new(states),
-            http_client,
+            states: Arc::new(RwLock::new(states)),
+            http_client: Arc::new(http_client),
+            refreshes: Arc::new(Mutex::new(HashMap::new())),
         }
     }
 
@@ -326,9 +342,38 @@ impl ProviderRuntime {
         provider_id: &str,
         config: &OidcProviderConfig,
     ) -> Result<ProviderState, String> {
-        self.recover_provider_state(provider_id, config)
+        let refresh = self
+            .refreshes
+            .lock()
+            .map_err(|_| "provider refresh registry is unavailable".to_string())?
+            .entry(provider_id.to_string())
+            .or_default()
+            .clone();
+        let mut attempt = refresh.lock_owned().await;
+        if let Some((completed, result)) = attempt.as_ref()
+            && completed.elapsed() < OIDC_JWKS_REFRESH_COOLDOWN
+        {
+            return result.clone();
+        }
+
+        // The admitted fetch owns the per-provider lock. A disconnected request
+        // cannot abandon discovery while consuming the provider's cooldown.
+        // Waiting callers share its completed result, including genuine failures.
+        let runtime = tokio::runtime::Handle::try_current().map_err(|err| err.to_string())?;
+        let provider_runtime = self.clone();
+        let provider_id = provider_id.to_string();
+        let config = config.clone();
+        runtime
+            .spawn(async move {
+                let result = provider_runtime
+                    .recover_provider_state(&provider_id, &config)
+                    .await
+                    .map_err(|err| err.to_string());
+                *attempt = Some((Instant::now(), result.clone()));
+                result
+            })
             .await
-            .map_err(|err| err.to_string())
+            .map_err(|err| err.to_string())?
     }
 
     pub(super) async fn recover_provider_state(
diff --git a/crates/iam/src/oidc/provider_tests.rs b/crates/iam/src/oidc/provider_tests.rs
index ba46832dd..9003521db 100644
--- a/crates/iam/src/oidc/provider_tests.rs
+++ b/crates/iam/src/oidc/provider_tests.rs
@@ -180,7 +180,7 @@ fn workload_metadata_rejects_duplicate_fields() {
     }
 }
 #[test]
-fn workload_verifier_preserves_algorithm_secret_and_audience_policy() {
+fn caller_supplied_tokens_cannot_be_signed_with_the_client_secret() {
     let secret = Nonce::new_random().secret().to_string();
     let mut config = build_mocked_oidc_provider_config("workload", "https://issuer.example.com");
     config.client_secret = Some(secret.clone());
@@ -195,7 +195,8 @@ fn workload_verifier_preserves_algorithm_secret_and_audience_policy() {
     let token: CoreIdToken = signed.parse().unwrap();
     for workload in [false, true] {
         for (algorithms, accepted) in [
-            (serde_json::json!(["HS256", "unsupported-future-algorithm"]), true),
+            (serde_json::json!(["RS256", "HS256"]), false),
+            (serde_json::json!(["HS256", "unsupported-future-algorithm"]), false),
             (serde_json::json!(["ES256"]), false),
             (serde_json::json!(["unsupported-future-algorithm"]), false),
         ] {
@@ -216,21 +217,6 @@ fn workload_verifier_preserves_algorithm_secret_and_audience_policy() {
                 accepted,
                 "workload={workload}, algorithms={algorithms}"
             );
-            if accepted {
-                assert!(
-                    token.claims(&metadata.verifier(&config), |_: Option<&Nonce>| Ok(())).is_err(),
-                    "additional audiences require explicit trust"
-                );
-                let mut wrong_secret = config.clone();
-                wrong_secret.client_secret = Some(Nonce::new_random().secret().to_string());
-                let verifier = metadata
-                    .verifier(&wrong_secret)
-                    .set_other_audience_verifier_fn(|aud| trusted_aud(&config.other_audiences, aud));
-                assert!(
-                    token.claims(&verifier, |_: Option<&Nonce>| Ok(())).is_err(),
-                    "incorrect client secret must fail"
-                );
-            }
         }
     }
 }
@@ -274,6 +260,19 @@ fn configured_verifier_rejects_malformed_hmac_signature_lengths() {
             let metadata = DiscoveredProviderMetadata::parse(&serde_json::to_vec(&document).expect("encode metadata"), true)
                 .expect("parse configured provider metadata");
             let verifier = metadata.verifier(&config);
+            assert!(
+                verify_id_token_claims(&valid, &verifier, |_: Option<&Nonce>| Ok(())).is_err(),
+                "caller-supplied HMAC tokens must be rejected"
+            );
+            // The authorization-code flow obtains tokens directly from the
+            // provider and still supports confidential-client verification.
+            let verifier = openidconnect::core::CoreIdTokenVerifier::new_confidential_client(
+                openidconnect::ClientId::new(config.client_id.clone()),
+                openidconnect::ClientSecret::new(secret.to_owned()),
+                metadata.issuer().clone(),
+                openidconnect::core::CoreJsonWebKeySet::new(vec![]),
+            )
+            .set_allowed_algs(vec![serde_json::from_value(serde_json::json!(name)).expect("parse signing algorithm")]);
             assert!(
                 verify_id_token_claims(&valid, &verifier, |_: Option<&Nonce>| Ok(())).is_ok(),
                 "valid {name} token must pass for workload={workload}"
@@ -780,3 +779,149 @@ async fn test_validate_oidc_provider_config_returns_detailed_errors() {
     assert!(err.contains(&format!("issuer '{base}/application/o/rustfs/'")));
     assert!(handle.join().is_ok());
 }
+
+#[tokio::test]
+async fn jwks_refresh_is_single_flight_and_survives_request_cancellation() {
+    let (initial_key, initial_jwk) = oidc_es256_key_and_jwk("initial");
+    let (rotated_key, rotated_jwk) = oidc_es256_key_and_jwk("rotated");
+    let (wrong_key, _) = oidc_es256_key_and_jwk("wrong");
+    let requests = Arc::new(AtomicUsize::new(0));
+    let started = Arc::new(tokio::sync::Notify::new());
+    let (release_tx, release_rx) = std::sync::mpsc::channel();
+    let server_requests = Arc::clone(&requests);
+    let server_started = Arc::clone(&started);
+    let Some((base, server)) = start_mock_oidc_discovery_server_with_jwks(
+        |base| (base.to_string(), format!("{base}/jwks"), "/jwks".to_string()),
+        6,
+        "ES256",
+        false,
+        move |fetch| {
+            let request = server_requests.fetch_add(1, Ordering::SeqCst);
+            if request == 2 {
+                server_started.notify_one();
+                release_rx
+                    .recv_timeout(StdDuration::from_secs(5))
+                    .expect("release refresh response");
+            }
+            serde_json::json!({"keys": [if fetch == 0 { &initial_jwk } else { &rotated_jwk }]}).to_string()
+        },
+    ) else {
+        return;
+    };
+    let mut config = build_mocked_oidc_provider_config("bounded-refresh", &base);
+    config.issuer = Some(base.clone());
+    let http = ReqwestHttpClient::with_policy(OutboundPolicy::from_allowed_origins(&base).expect("allow test origin"));
+    let state = discover_provider(&config, &http).await.expect("initial discovery");
+    let sys = Arc::new(OidcSys {
+        configs: HashMap::from([(config.id.clone(), test_sourced_config(config.clone()))]),
+        provider_runtime: ProviderRuntime::new(http, HashMap::from([(config.id.clone(), state)])),
+        state_store: OidcStateStore::new(),
+        pending_discovery: Default::default(),
+    });
+    let now = time::OffsetDateTime::now_utc().unix_timestamp();
+    let payload = serde_json::json!({"iss": base, "sub": "user", "aud": config.client_id, "iat": now, "exp": now + 300});
+    let sign = |kid: &str, claims: &serde_json::Value, key: &EncodingKey| {
+        let mut header = Header::new(Algorithm::ES256);
+        header.kid = Some(kid.to_string());
+        jsonwebtoken::encode(&header, claims, key).expect("sign test token")
+    };
+    for (claim, value) in [
+        ("aud", serde_json::json!("wrong-audience")),
+        ("exp", serde_json::json!(now - 300)),
+    ] {
+        let mut invalid = payload.clone();
+        invalid[claim] = value;
+        assert!(
+            sys.verify_web_identity_token(&sign("initial", &invalid, &initial_key))
+                .await
+                .is_err()
+        );
+    }
+    assert_eq!(requests.load(Ordering::SeqCst), 2, "claim failures cannot refresh signing keys");
+    let invalid = sign("rotated", &payload, &wrong_key);
+    let attack = {
+        let sys = Arc::clone(&sys);
+        let invalid = invalid.clone();
+        tokio::spawn(async move { sys.verify_web_identity_token(&invalid).await })
+    };
+    tokio::time::timeout(StdDuration::from_secs(5), started.notified())
+        .await
+        .expect("refresh started");
+    attack.abort();
+    assert!(attack.await.expect_err("request canceled").is_cancelled());
+    let mut retries = Vec::new();
+    for _ in 0..16 {
+        let sys = Arc::clone(&sys);
+        let invalid = invalid.clone();
+        retries.push(tokio::spawn(async move { sys.verify_web_identity_token(&invalid).await }));
+    }
+    release_tx.send(()).expect("release provider");
+    for retry in retries {
+        assert!(
+            tokio::time::timeout(StdDuration::from_secs(5), retry)
+                .await
+                .expect("retry timeout")
+                .expect("retry join")
+                .is_err()
+        );
+    }
+    let rotated = sign("rotated", &payload, &rotated_key);
+    sys.verify_web_identity_token(&rotated)
+        .await
+        .expect("completed refresh must accept rotated keys after the original caller left");
+    assert_eq!(requests.load(Ordering::SeqCst), 4, "one discovery/JWKS pair for all rejected tokens");
+    sys.provider_runtime
+        .refresh_provider_state("independent-provider", &config)
+        .await
+        .expect("provider cooldowns must be independent");
+    assert_eq!(requests.load(Ordering::SeqCst), 6);
+    server.join().expect("mock server");
+}
+
+#[tokio::test]
+async fn jwks_refresh_cools_down_failures_and_recovers_after_the_interval() {
+    let (_, initial_jwk) = oidc_es256_key_and_jwk("initial");
+    let (_, recovered_jwk) = oidc_es256_key_and_jwk("recovered");
+    let requests = Arc::new(AtomicUsize::new(0));
+    let server_requests = Arc::clone(&requests);
+    let Some((base, server)) = start_mock_oidc_discovery_server_with_jwks(
+        |base| (base.to_string(), format!("{base}/jwks"), "/jwks".to_string()),
+        6,
+        "ES256",
+        false,
+        move |fetch| {
+            server_requests.fetch_add(1, Ordering::SeqCst);
+            match fetch {
+                0 => serde_json::json!({"keys": [initial_jwk]}).to_string(),
+                1 => "invalid JWKS".to_string(),
+                _ => serde_json::json!({"keys": [recovered_jwk]}).to_string(),
+            }
+        },
+    ) else {
+        return;
+    };
+    let mut config = build_mocked_oidc_provider_config("recovering-refresh", &base);
+    config.issuer = Some(base.clone());
+    let http = ReqwestHttpClient::with_policy(OutboundPolicy::from_allowed_origins(&base).expect("allow test origin"));
+    let initial = discover_provider(&config, &http).await.expect("initial discovery");
+    let runtime = ProviderRuntime::new(http, HashMap::from([(config.id.clone(), initial.clone())]));
+    assert!(runtime.refresh_provider_state(&config.id, &config).await.is_err());
+    assert_eq!(requests.load(Ordering::SeqCst), 4);
+    for _ in 0..8 {
+        assert!(runtime.refresh_provider_state(&config.id, &config).await.is_err());
+    }
+    assert_eq!(requests.load(Ordering::SeqCst), 4, "completed failures also consume a bounded cooldown");
+    assert_eq!(
+        runtime.get_provider_state(&config.id).expect("cached keys").discovered_at,
+        initial.discovered_at
+    );
+    let refresh = runtime.refreshes.lock().expect("registry")[&config.id].clone();
+    refresh.lock().await.as_mut().expect("completed attempt").0 = Instant::now() - OIDC_JWKS_REFRESH_COOLDOWN;
+    runtime
+        .refresh_provider_state(&config.id, &config)
+        .await
+        .expect("retry after cooldown");
+    assert_eq!(requests.load(Ordering::SeqCst), 6);
+    assert!(runtime.get_provider_state(&config.id).expect("recovered keys").discovered_at > initial.discovered_at);
+    server.join().expect("mock server");
+}
diff --git a/crates/iam/src/oidc/runtime.rs b/crates/iam/src/oidc/runtime.rs
index 3a41e84d7..c55045312 100644
--- a/crates/iam/src/oidc/runtime.rs
+++ b/crates/iam/src/oidc/runtime.rs
@@ -33,8 +33,8 @@ use crate::{
 };
 use openidconnect::core::{CoreAuthenticationFlow, CoreClient, CoreIdToken};
 use openidconnect::{
-    Audience, AuthType, AuthorizationCode, ClientId, ClientSecret, CsrfToken, LogoutRequest, Nonce, PkceCodeChallenge,
-    PkceCodeVerifier, PostLogoutRedirectUrl, RedirectUrl, RequestTokenError, Scope,
+    Audience, AuthType, AuthorizationCode, ClaimsVerificationError, ClientId, ClientSecret, CsrfToken, LogoutRequest, Nonce,
+    PkceCodeChallenge, PkceCodeVerifier, PostLogoutRedirectUrl, RedirectUrl, RequestTokenError, Scope,
 };
 use rustfs_policy::policy::{ClaimLookup, get_claim_case_insensitive};
 use rustfs_utils::logging::LogThrottle;
@@ -537,6 +537,9 @@ impl OidcSys {
             .set_other_audience_verifier_fn(|aud| trusted_aud(&config.other_audiences, aud));
         let verified = verify_id_token_claims(id_token, &verifier, &Nonce::new(session.nonce.clone()));
         if let Err(e) = verified {
+            if !matches!(e, ClaimsVerificationError::SignatureVerification(_)) {
+                return Err(format!("ID token verification failed: {e}"));
+            }
             let verification_error = e.to_string();
             warn!(
                 event = EVENT_OIDC_DIAGNOSTICS,
@@ -767,6 +770,9 @@ impl OidcSys {
             .verifier(&config)
             .set_other_audience_verifier_fn(|aud| trusted_aud(&config.other_audiences, aud));
         if let Err(e) = verify_id_token_claims(&id_token, &verifier, |_: Option<&Nonce>| Ok(())) {
+            if !matches!(e, ClaimsVerificationError::SignatureVerification(_)) {
+                return Err(format!("ID token verification failed: {e}"));
+            }
             state = self
                 .provider_runtime
                 .refresh_provider_state(&provider_id, &config)
diff --git a/crates/iam/src/storage_api.rs b/crates/iam/src/storage_api.rs
index 009c866f5..76468581d 100644
--- a/crates/iam/src/storage_api.rs
+++ b/crates/iam/src/storage_api.rs
@@ -14,6 +14,20 @@
 
 use std::sync::Arc;
 
+pub(crate) fn is_unreadable_bucket_tags(error: &crate::error::Error) -> bool {
+    let crate::error::Error::Io(error) = error else {
+        return false;
+    };
+    let Some(storage_error) = error.get_ref().and_then(|inner| inner.downcast_ref::<IamStorageError>()) else {
+        return false;
+    };
+    rustfs_ecstore::api::bucket::metadata::unreadable_config_refusal(storage_error)
+        .is_some_and(|failure| failure.config_file == rustfs_ecstore::api::bucket::metadata::BUCKET_TAGGING_CONFIG)
+}
+
+#[cfg(test)]
+pub(crate) use rustfs_ecstore::api::bucket::metadata::UnreadableBucketConfig;
+
 pub(crate) use rustfs_ecstore::api::config::RUSTFS_CONFIG_PREFIX as IAM_CONFIG_ROOT_PREFIX;
 use rustfs_ecstore::api::config::com::{
     delete_config as ecstore_delete_config, read_config_no_lock as ecstore_read_config_no_lock,
diff --git a/crates/iam/src/store/object.rs b/crates/iam/src/store/object.rs
index bfed0c301..d3a539ea5 100644
--- a/crates/iam/src/store/object.rs
+++ b/crates/iam/src/store/object.rs
@@ -1154,7 +1154,7 @@ impl Store for ObjectStore {
         // node-counted lock quorum (rustfs#4304; startup contract rustfs#4056).
         const LOAD_ALL_MODE: LoadMode = LoadMode::BootstrapNoLock;
 
-        let cache_snapshot = cache.snapshot();
+        let reload = cache.begin_reload().await;
         let listed_config_items = self.list_all_iamconfig_items().await?;
 
         let mut policy_docs_cache = CacheEntity::new(get_default_policies());
@@ -1201,26 +1201,20 @@ impl Store for ObjectStore {
         }
 
         // groups
-        let mut groups_cache = None;
+        let mut groups_cache = CacheEntity::default();
         if let Some(item_name_list) = listed_config_items.get(GROUPS_LIST_KEY) {
-            let mut items_cache = CacheEntity::default();
-
             for item in item_name_list.iter() {
                 let name = rustfs_utils::path::dir(item);
                 debug!(group = %name, "IAM group loaded");
-                if let Err(err) = self.load_group_with(&name, &mut items_cache, LOAD_ALL_MODE).await {
+                if let Err(err) = self.load_group_with(&name, &mut groups_cache, LOAD_ALL_MODE).await {
                     return Err(Error::other(format!("load group failed: {err}")));
                 };
             }
-
-            groups_cache = Some(items_cache);
         }
 
         // user policies
-        let mut user_policies_cache = None;
+        let mut user_policies_cache = CacheEntity::default();
         if let Some(item_name_list) = listed_config_items.get(POLICY_DB_USERS_LIST_KEY) {
-            let mut items_cache = CacheEntity::default();
-
             // Load in fixed-size chunks so each mapping is fetched exactly once
             // (backlog#806 — the split_off loop was O(n^2)).
             for chunk in item_name_list.chunks(32) {
@@ -1235,32 +1229,26 @@ impl Store for ObjectStore {
 
                     let name = chunk[idx].trim_end_matches(".json").to_owned();
                     debug!(user = %name, "IAM user policy loaded");
-                    items_cache.insert(name, p);
+                    user_policies_cache.insert(name, p);
                 }
             }
-
-            user_policies_cache = Some(items_cache);
         }
 
         // group policy
-        let mut group_policies_cache = None;
+        let mut group_policies_cache = CacheEntity::default();
         if let Some(item_name_list) = listed_config_items.get(POLICY_DB_GROUPS_LIST_KEY) {
-            let mut items_cache = CacheEntity::default();
-
             for item in item_name_list.iter() {
                 let name = item.trim_end_matches(".json");
 
                 debug!(group = %name, "IAM group policy loaded");
                 if let Err(err) = self
-                    .load_mapped_policy_with(name, UserType::Reg, true, &mut items_cache, LOAD_ALL_MODE)
+                    .load_mapped_policy_with(name, UserType::Reg, true, &mut group_policies_cache, LOAD_ALL_MODE)
                     .await
                     && !is_err_no_such_policy(&err)
                 {
                     return Err(Error::other(format!("load group policy failed: {err}")));
                 };
             }
-
-            group_policies_cache = Some(items_cache);
         }
 
         let mut sts_policies_cache = CacheEntity::default();
@@ -1330,25 +1318,48 @@ impl Store for ObjectStore {
             }
         }
 
+        #[cfg(test)]
+        if let Ok(barrier) = LOAD_ALL_COMMIT_BARRIER.try_with(std::sync::Arc::clone) {
+            barrier.0.notify_one();
+            barrier.1.notified().await;
+        }
+
         cache.with_write_lock(|cache| {
-            if cache.matches_snapshot(&cache_snapshot) {
-                cache.replace_policy_docs(policy_docs_cache);
-                if let Some(groups_cache) = groups_cache {
-                    cache.replace_groups(groups_cache);
-                }
-                if let Some(user_policies_cache) = user_policies_cache {
-                    cache.replace_user_policies(user_policies_cache);
-                }
-                if let Some(group_policies_cache) = group_policies_cache {
-                    cache.replace_group_policies(group_policies_cache);
-                }
-                cache.replace_users(user_items_cache);
-                cache.replace_sts_accounts(sts_items_cache);
-                cache.replace_sts_policies(sts_policies_cache);
-                cache.build_user_group_memberships();
-            } else {
-                warn!("IAM full reload cache commit skipped due to concurrent cache changes");
-            }
+            reload.merge_partition(
+                crate::cache::CachePartition::PolicyDocs,
+                &mut policy_docs_cache,
+                &cache.state().policy_docs,
+            );
+            reload.merge_partition(crate::cache::CachePartition::Groups, &mut groups_cache, &cache.state().groups);
+            reload.merge_partition(
+                crate::cache::CachePartition::UserPolicies,
+                &mut user_policies_cache,
+                &cache.state().user_policies,
+            );
+            reload.merge_partition(
+                crate::cache::CachePartition::GroupPolicies,
+                &mut group_policies_cache,
+                &cache.state().group_policies,
+            );
+            reload.merge_partition(crate::cache::CachePartition::Users, &mut user_items_cache, &cache.state().users);
+            reload.merge_partition(
+                crate::cache::CachePartition::StsAccounts,
+                &mut sts_items_cache,
+                &cache.state().sts_accounts,
+            );
+            reload.merge_partition(
+                crate::cache::CachePartition::StsPolicies,
+                &mut sts_policies_cache,
+                &cache.state().sts_policies,
+            );
+            cache.replace_policy_docs(policy_docs_cache);
+            cache.replace_groups(groups_cache);
+            cache.replace_user_policies(user_policies_cache);
+            cache.replace_group_policies(group_policies_cache);
+            cache.replace_users(user_items_cache);
+            cache.replace_sts_accounts(sts_items_cache);
+            cache.replace_sts_policies(sts_policies_cache);
+            cache.build_user_group_memberships();
         });
 
         Ok(())
@@ -1363,6 +1374,11 @@ fn map_delete_user_identity_error(name: &str, err: Error) -> Error {
     }
 }
 
+#[cfg(test)]
+tokio::task_local! {
+    static LOAD_ALL_COMMIT_BARRIER: std::sync::Arc<(tokio::sync::Notify, tokio::sync::Notify)>;
+}
+
 #[cfg(test)]
 mod tests {
     use super::{DecryptSource, LoadMode, ObjectStore, map_delete_user_identity_error};
@@ -1372,6 +1388,99 @@ mod tests {
     use serial_test::serial;
     use temp_env::with_vars;
 
+    #[test]
+    #[serial]
+    fn test_load_all_clears_partitions_with_empty_prefix() {
+        use crate::cache::Cache;
+        use crate::store::{GroupInfo, MappedPolicy, Store, UserType};
+
+        std::thread::Builder::new()
+            .stack_size(8 * 1024 * 1024)
+            .spawn(|| {
+                let runtime = tokio::runtime::Builder::new_multi_thread()
+                    .worker_threads(2)
+                    .enable_all()
+                    .build()
+                    .expect("build IAM reload test runtime");
+                runtime.block_on(async {
+                    let _credentials = test_cred();
+                    let temp = tempfile::tempdir().expect("create IAM reload store directory");
+                    let env = Box::pin(
+                        rustfs_test_utils::TestECStoreEnv::builder()
+                            .base_dir(temp.path())
+                            .init_bucket_metadata(false)
+                            .build(),
+                    )
+                    .await;
+                    let store = ObjectStore::new(env.ecstore);
+                    store
+                        .save_group_info("reload-group", GroupInfo::new(vec!["reload-user".to_string()]))
+                        .await
+                        .expect("seed group membership");
+                    store
+                        .save_mapped_policy("reload-user", UserType::Reg, false, MappedPolicy::new("readwrite"), None)
+                        .await
+                        .expect("seed user policy");
+                    store
+                        .save_mapped_policy("reload-group", UserType::Reg, true, MappedPolicy::new("readonly"), None)
+                        .await
+                        .expect("seed group policy");
+
+                    let cache = Cache::default();
+                    store.load_all(&cache).await.expect("load nonempty IAM partitions");
+                    {
+                        let snapshot = cache.snapshot();
+                        assert!(snapshot.groups.contains_key("reload-group"));
+                        assert_eq!(snapshot.user_policies["reload-user"].policies, "readwrite");
+                        assert_eq!(snapshot.group_policies["reload-group"].policies, "readonly");
+                        assert!(snapshot.user_group_memberships["reload-user"].contains("reload-group"));
+                    }
+
+                    // Mutate durable state without notifying this cache, as on
+                    // a peer that missed the last mapping/group deletion.
+                    store
+                        .delete_mapped_policy("reload-user", UserType::Reg, false)
+                        .await
+                        .expect("remove last user mapping");
+                    store
+                        .delete_mapped_policy("reload-group", UserType::Reg, true)
+                        .await
+                        .expect("remove last group mapping");
+                    store.delete_group_info("reload-group").await.expect("remove last group");
+                    assert!(cache.snapshot().groups.contains_key("reload-group"));
+                    // Simulate a missed peer revocation while STS publication
+                    // and a separate user update overlap this full disk reload.
+                    let stale = rustfs_policy::auth::UserIdentity {
+                        version: 1,
+                        ..Default::default()
+                    };
+                    cache.add_or_update_user("revoked-user", &stale, time::OffsetDateTime::now_utc());
+                    let barrier = std::sync::Arc::new((tokio::sync::Notify::new(), tokio::sync::Notify::new()));
+                    let loading = super::LOAD_ALL_COMMIT_BARRIER.scope(std::sync::Arc::clone(&barrier), store.load_all(&cache));
+                    let concurrent = async {
+                        barrier.0.notified().await;
+                        cache.add_or_update_sts_account("new-session", &stale, time::OffsetDateTime::now_utc());
+                        cache.add_or_update_user("new-service", &stale, time::OffsetDateTime::now_utc());
+                        barrier.1.notify_one();
+                    };
+                    let (loaded, ()) = tokio::join!(loading, concurrent);
+                    loaded.expect("reconcile revoked identities despite STS traffic");
+                    let snapshot = cache.snapshot();
+                    assert!(!snapshot.users.contains_key("revoked-user"));
+                    assert!(snapshot.users.contains_key("new-service"));
+                    assert!(snapshot.sts_accounts.contains_key("new-session"));
+                    assert!(snapshot.groups.is_empty());
+                    assert!(snapshot.user_policies.is_empty());
+                    assert!(snapshot.group_policies.is_empty());
+                    assert!(snapshot.user_group_memberships.is_empty());
+                    assert!(!snapshot.policy_docs.is_empty(), "built-in policies must remain available");
+                });
+            })
+            .expect("spawn IAM reload test thread")
+            .join()
+            .expect("IAM reload test should complete");
+    }
+
     /// rustfs#4304 / startup contract rustfs#4056: the bulk snapshot load
     /// (`load_all`) must never depend on the node-counted namespace lock
     /// quorum, so its reads have to carry `no_lock = true` down to the
diff --git a/crates/iam/src/sys.rs b/crates/iam/src/sys.rs
index e99e7099b..3b3b7baee 100644
--- a/crates/iam/src/sys.rs
+++ b/crates/iam/src/sys.rs
@@ -45,6 +45,7 @@ use std::borrow::Cow;
 use std::collections::{HashMap, HashSet};
 use std::sync::Arc;
 use std::sync::OnceLock;
+use subtle::ConstantTimeEq;
 use time::OffsetDateTime;
 use tokio::sync::RwLock;
 use tracing::{error, info, warn};
@@ -149,6 +150,7 @@ fn get_policy_plugin_state() -> Arc<RwLock<PolicyPluginState>> {
         .clone()
 }
 
+#[derive(Clone)]
 pub struct IamSys<T> {
     store: Arc<IamCache<T>>,
     roles_map: HashMap<ARN, String>,
@@ -167,6 +169,16 @@ enum PreparedServicePolicyMode {
     SessionBound,
 }
 
+tokio::task_local! {
+    static BUCKET_TAG_DELETION: ();
+}
+
+/// Scope authorization to the server's DeleteBucketTagging operation. The IAM action is shared
+/// with PutBucketTagging, so policy arguments and client headers cannot identify this repair path.
+pub async fn with_bucket_tag_deletion<F: std::future::Future>(operation: F) -> F::Output {
+    BUCKET_TAG_DELETION.scope((), operation).await
+}
+
 #[derive(Clone)]
 enum PreparedIamMode {
     TerminalDeny,
@@ -688,6 +700,54 @@ impl<T: Store> IamSys<T> {
         Ok(updated_at)
     }
 
+    /// Publish a SigV4-derived session only while its authenticated parent is
+    /// unchanged. The parent lock spans validation and durable publication, so
+    /// rotation/deletion either precedes this check or observes the new session.
+    /// Canceling the caller does not cancel an admitted storage write or release
+    /// its parent lock before publication completes.
+    pub async fn set_temp_user_from_parent(
+        &self,
+        cred: &Credentials,
+        authenticated_parent: &Credentials,
+    ) -> Result<OffsetDateTime> {
+        let runtime = tokio::runtime::Handle::try_current().map_err(Error::other)?;
+        let iam = self.clone();
+        let cred = cred.clone();
+        let authenticated_parent = authenticated_parent.clone();
+        runtime
+            .spawn(async move { iam.set_temp_user_from_parent_inner(&cred, &authenticated_parent).await })
+            .await
+            .map_err(Error::other)?
+    }
+
+    async fn set_temp_user_from_parent_inner(
+        &self,
+        cred: &Credentials,
+        authenticated_parent: &Credentials,
+    ) -> Result<OffsetDateTime> {
+        if cred.parent_user != authenticated_parent.access_key {
+            return Err(IamError::IAMActionNotAllowed);
+        }
+        let parent_lock = self.store.cache.parent_mutation_lock(&cred.parent_user);
+        let _parent_guard = parent_lock.lock().await;
+        let parent = if crate::is_root_access_key(&cred.parent_user) {
+            crate::root_credentials::credentials()
+        } else {
+            self.store.get_user(&cred.parent_user).await.map(|user| user.credentials)
+        };
+        let Some(parent) = parent else {
+            return Err(IamError::IAMActionNotAllowed);
+        };
+        if !parent.is_valid()
+            || parent.is_temp()
+            || parent.is_service_account()
+            || !bool::from(parent.secret_key.as_bytes().ct_eq(authenticated_parent.secret_key.as_bytes()))
+        {
+            return Err(IamError::IAMActionNotAllowed);
+        }
+        self.set_temp_user(&cred.access_key, cred, None).await
+    }
+
     pub async fn is_temp_user(&self, name: &str) -> Result<(bool, String)> {
         let Some(u) = self.store.get_user(name).await else {
             return Err(IamError::NoSuchUser(name.to_string()));
@@ -753,6 +813,13 @@ impl<T: Store> IamSys<T> {
         opts: NewServiceAccountOpts,
         updated_at: OffsetDateTime,
     ) -> Result<(Credentials, OffsetDateTime)> {
+        if !opts.access_key.is_empty()
+            && (opts.access_key.trim() == "."
+                || opts.access_key.trim() == ".."
+                || opts.access_key.chars().any(|ch| ch.is_control() || matches!(ch, '/' | '\\')))
+        {
+            return Err(IamError::InvalidArgument);
+        }
         if parent_user.is_empty() {
             return Err(IamError::InvalidArgument);
         }
@@ -983,7 +1050,7 @@ impl<T: Store> IamSys<T> {
             }
         };
 
-        if !sa.credentials.is_temp() {
+        if sa.credentials.is_service_account() || !sa.credentials.is_temp() {
             return Err(IamError::NoSuchTempAccount(access_key.to_string()));
         }
 
@@ -1061,11 +1128,38 @@ impl<T: Store> IamSys<T> {
 
     /// [`Self::create_user`] stamping the identity with `updated_at` (a
     /// replicated edit's source time) instead of the local clock (backlog#2291).
+    /// Once admitted, persistence and session revocation continue if the caller
+    /// stops waiting. A revocation error can follow a persisted secret change.
     pub async fn create_user_at(
         &self,
         access_key: &str,
         args: &AddOrUpdateUserReq,
         updated_at: OffsetDateTime,
+    ) -> Result<OffsetDateTime> {
+        let runtime = tokio::runtime::Handle::try_current().map_err(Error::other)?;
+        let iam = self.clone();
+        let access_key = access_key.to_string();
+        let args = args.clone();
+        #[cfg(test)]
+        let notification_probe = crate::LOAD_USER_NOTIFICATION_PROBE.try_with(Arc::clone).ok();
+        let operation = async move { iam.create_user_at_inner(&access_key, &args, updated_at).await };
+        #[cfg(test)]
+        let task = runtime.spawn(async move {
+            if let Some(probe) = notification_probe {
+                return crate::LOAD_USER_NOTIFICATION_PROBE.scope(probe, operation).await;
+            }
+            operation.await
+        });
+        #[cfg(not(test))]
+        let task = runtime.spawn(operation);
+        task.await.map_err(Error::other)?
+    }
+
+    async fn create_user_at_inner(
+        &self,
+        access_key: &str,
+        args: &AddOrUpdateUserReq,
+        updated_at: OffsetDateTime,
     ) -> Result<OffsetDateTime> {
         if !is_access_key_valid(access_key) {
             return Err(IamError::InvalidAccessKeyLength);
@@ -1079,9 +1173,15 @@ impl<T: Store> IamSys<T> {
             return Err(IamError::InvalidSecretKeyLength);
         }
 
-        let updated_at = self.store.add_user_at(access_key, args, updated_at).await?;
+        let (updated_at, secret_changed, parent_guard) = self
+            .store
+            .add_user_at_with_secret_change(access_key, args, updated_at)
+            .await?;
+        if secret_changed {
+            self.revoke_sts_sessions_for_parent(access_key).await?;
+        }
+        drop(parent_guard);
         self.load_user(access_key, UserType::Reg).await?;
-
         self.notify_for_user(access_key, false).await;
 
         Ok(updated_at)
@@ -1092,6 +1192,71 @@ impl<T: Store> IamSys<T> {
         access_key: &str,
         secret_key: &str,
     ) -> Result<(OffsetDateTime, rustfs_madmin::AccountStatus)> {
+        self.rotate_user_secret_key(access_key, secret_key)
+            .await
+            .map(|(updated_at, status, _revoked)| (updated_at, status))
+    }
+
+    /// Rotate a secret and revoke its STS sessions under one parent mutation lock.
+    /// A revocation error is returned after the new secret has been persisted;
+    /// callers must not report the rotation as fully completed in that case.
+    /// An admitted rotation continues through revocation after caller cancellation.
+    pub async fn rotate_user_secret_key(
+        &self,
+        access_key: &str,
+        secret_key: &str,
+    ) -> Result<(OffsetDateTime, rustfs_madmin::AccountStatus, usize)> {
+        self.rotate_user_secret_key_checked(access_key, secret_key, None).await
+    }
+
+    /// Change an enabled regular caller's secret only if its signing secret is
+    /// still current under the parent mutation lock. Status and policies are kept.
+    /// Persistence and revocation continue after caller cancellation.
+    pub async fn change_own_secret_key(
+        &self,
+        access_key: &str,
+        expected_secret: &str,
+        secret_key: &str,
+    ) -> Result<(OffsetDateTime, rustfs_madmin::AccountStatus, usize)> {
+        self.rotate_user_secret_key_checked(access_key, secret_key, Some(expected_secret))
+            .await
+    }
+
+    async fn rotate_user_secret_key_checked(
+        &self,
+        access_key: &str,
+        secret_key: &str,
+        expected_secret: Option<&str>,
+    ) -> Result<(OffsetDateTime, rustfs_madmin::AccountStatus, usize)> {
+        let runtime = tokio::runtime::Handle::try_current().map_err(Error::other)?;
+        let iam = self.clone();
+        let access_key = access_key.to_string();
+        let secret_key = secret_key.to_string();
+        let expected_secret = expected_secret.map(str::to_string);
+        #[cfg(test)]
+        let notification_probe = crate::LOAD_USER_NOTIFICATION_PROBE.try_with(Arc::clone).ok();
+        let operation = async move {
+            iam.rotate_user_secret_key_inner(&access_key, &secret_key, expected_secret.as_deref())
+                .await
+        };
+        #[cfg(test)]
+        let task = runtime.spawn(async move {
+            if let Some(probe) = notification_probe {
+                return crate::LOAD_USER_NOTIFICATION_PROBE.scope(probe, operation).await;
+            }
+            operation.await
+        });
+        #[cfg(not(test))]
+        let task = runtime.spawn(operation);
+        task.await.map_err(Error::other)?
+    }
+
+    async fn rotate_user_secret_key_inner(
+        &self,
+        access_key: &str,
+        secret_key: &str,
+        expected_secret: Option<&str>,
+    ) -> Result<(OffsetDateTime, rustfs_madmin::AccountStatus, usize)> {
         if !is_access_key_valid(access_key) {
             return Err(IamError::InvalidAccessKeyLength);
         }
@@ -1100,9 +1265,14 @@ impl<T: Store> IamSys<T> {
             return Err(IamError::InvalidSecretKeyLength);
         }
 
-        let (updated_at, status) = self.store.update_user_secret_key(access_key, secret_key).await?;
+        let (updated_at, status, parent_guard) = self
+            .store
+            .update_user_secret_key_with_guard(access_key, secret_key, expected_secret)
+            .await?;
+        let revoked = self.revoke_sts_sessions_for_parent(access_key).await?;
+        drop(parent_guard);
         self.notify_for_user(access_key, false).await;
-        Ok((updated_at, status))
+        Ok((updated_at, status, revoked))
     }
 
     /// Add SSH public key for a user (for SFTP authentication)
@@ -1145,6 +1315,11 @@ impl<T: Store> IamSys<T> {
         }
     }
 
+    /// Current built-in IAM groups for a user or a derived credential's parent.
+    pub fn user_group_memberships(&self, name: &str) -> Vec<String> {
+        self.store.user_group_memberships(name)
+    }
+
     pub async fn get_user(&self, access_key: &str) -> Option<UserIdentity> {
         match self.check_key(access_key).await {
             Ok((u, _)) => u,
@@ -1275,6 +1450,15 @@ impl<T: Store> IamSys<T> {
         self.store.policy_db_get(name, groups).await
     }
 
+    /// Resolve STS policies while preserving whether an explicit identity mapping supplied them.
+    pub async fn sts_policy_db_get_with_identity_mapping(
+        &self,
+        name: &str,
+        groups: &Option<Vec<String>>,
+    ) -> Result<(Vec<String>, bool)> {
+        self.store.sts_policy_db_get_with_identity_mapping(name, groups).await
+    }
+
     pub async fn sts_policy_db_get(&self, name: &str, groups: &Option<Vec<String>>) -> Result<Vec<String>> {
         self.store.sts_policy_db_get(name, groups).await
     }
@@ -1358,17 +1542,74 @@ impl<T: Store> IamSys<T> {
         Ok(Some(verified_claims))
     }
 
+    /// Create within the authenticated caller's scope and current parent revision.
+    /// An admitted write owns its parent lock until publication even if the caller
+    /// stops waiting; errors never publish a credential from a changed parent.
     pub async fn new_service_account_from_caller(
+        &self,
+        parent_user: &str,
+        groups: Option<Vec<String>>,
+        opts: NewServiceAccountOpts,
+        caller: &Credentials,
+    ) -> Result<(Credentials, OffsetDateTime, HashMap<String, Value>)> {
+        let runtime = tokio::runtime::Handle::try_current().map_err(Error::other)?;
+        let iam = self.clone();
+        let parent_user = parent_user.to_string();
+        let caller = caller.clone();
+        runtime
+            .spawn(async move {
+                iam.new_service_account_from_caller_inner(&parent_user, groups, opts, &caller)
+                    .await
+            })
+            .await
+            .map_err(Error::other)?
+    }
+
+    async fn new_service_account_from_caller_inner(
         &self,
         parent_user: &str,
         groups: Option<Vec<String>>,
         mut opts: NewServiceAccountOpts,
         caller: &Credentials,
     ) -> Result<(Credentials, OffsetDateTime, HashMap<String, Value>)> {
-        if parent_user != caller.access_key && parent_user != caller.parent_user {
+        if parent_user != caller.access_key && parent_user != caller.parent_user && !crate::is_root_access_key(&caller.access_key)
+        {
             return Err(IamError::IAMActionNotAllowed);
         }
 
+        let parent_lock = self.store.cache.parent_mutation_lock(parent_user);
+        let _parent_guard = parent_lock.lock().await;
+        let federated_parent = if caller.is_service_account() {
+            is_valid_verified_federated_policy(caller.claims_or_empty(), parent_user)
+        } else {
+            is_verified_or_legacy_federated_session(caller.claims_or_empty(), parent_user)
+        };
+        if !crate::is_root_access_key(parent_user) && !federated_parent {
+            let Some(parent) = self.store.get_user(parent_user).await else {
+                return Err(IamError::IAMActionNotAllowed);
+            };
+            if !parent.credentials.is_valid()
+                || parent.credentials.is_temp()
+                || parent.credentials.is_service_account()
+                || (caller.access_key == parent_user
+                    && !bool::from(parent.credentials.secret_key.as_bytes().ct_eq(caller.secret_key.as_bytes())))
+            {
+                return Err(IamError::IAMActionNotAllowed);
+            }
+        }
+
+        if !federated_parent && caller.access_key != parent_user && !crate::is_root_access_key(&caller.access_key) {
+            let Some(current) = self.store.get_user(&caller.access_key).await else {
+                return Err(IamError::IAMActionNotAllowed);
+            };
+            if !current.credentials.is_valid()
+                || current.credentials.parent_user != parent_user
+                || !bool::from(current.credentials.secret_key.as_bytes().ct_eq(caller.secret_key.as_bytes()))
+            {
+                return Err(IamError::IAMActionNotAllowed);
+            }
+        }
+
         let verified_federated_policy = if caller.is_service_account() {
             None
         } else {
@@ -1486,10 +1727,41 @@ impl<T: Store> IamSys<T> {
             };
         }
         if let Some(prepared) = state.prepared_iam_auth() {
+            if matches!(prepared.mode, PreparedIamMode::Opa) && !self.external_auth_identity_is_active(args).await {
+                return PreparedIamAuth {
+                    needs_existing_object_tag: false,
+                    mode: PreparedIamMode::TerminalDeny,
+                };
+            }
             return prepared;
         }
         self.prepare_builtin_auth(args).await
     }
+    async fn external_auth_identity_is_active(&self, args: &Args<'_>) -> bool {
+        let Some(user) = self.store.get_user(args.account).await else {
+            // Anonymous and external identities can be authorized by the plugin;
+            // a derived credential that disappeared from IAM cannot.
+            return !args.claims.contains_key("parent");
+        };
+        let credentials = &user.credentials;
+        if !credentials.is_valid() {
+            return false;
+        }
+        if !credentials.is_service_account() && !credentials.is_temp() {
+            return true;
+        }
+        let parent = &credentials.parent_user;
+        let federated = if credentials.is_service_account() {
+            is_valid_verified_federated_policy(args.claims, parent)
+        } else {
+            is_verified_or_legacy_federated_session(args.claims, parent)
+        };
+        if federated || crate::is_root_access_key(parent) {
+            return true;
+        }
+        matches!(self.check_key(parent).await, Ok((Some(_), true)))
+    }
+
     async fn prepare_builtin_auth(&self, args: &Args<'_>) -> PreparedIamAuth {
         let Ok((is_svc, parent_user)) = self.is_service_account(args.account).await else {
             return PreparedIamAuth {
@@ -1544,7 +1816,20 @@ impl<T: Store> IamSys<T> {
                 let tags = if args.bucket.is_empty() {
                     HashMap::new()
                 } else {
-                    self.store.api.load_bucket_tags(args.bucket).await?
+                    match self.store.api.load_bucket_tags(args.bucket).await {
+                        Ok(tags) => tags,
+                        Err(error)
+                            if args.action
+                                == rustfs_policy::policy::action::Action::S3Action(
+                                    rustfs_policy::policy::action::S3Action::PutBucketTaggingAction,
+                                )
+                                && BUCKET_TAG_DELETION.try_with(|()| true).unwrap_or(false)
+                                && crate::storage_api::is_unreadable_bucket_tags(&error) =>
+                        {
+                            HashMap::new()
+                        }
+                        Err(error) => return Err(error),
+                    }
                 };
                 let conditions = opa_bucket_tag_conditions(args.conditions, tags);
                 opa_enable
@@ -2008,6 +2293,9 @@ pub fn is_safe_claim_policy_name(policy: &str) -> bool {
     has_alnum
 }
 
+/// Verified upstream issuer preserved separately from RustFS's session marker.
+pub const OIDC_ISSUER_CLAIM: &str = "x-rustfs-internal-oidc-issuer";
+
 pub fn is_rustfs_oidc_claims(claims: &HashMap<String, Value>) -> bool {
     claims.get("iss").and_then(Value::as_str) == Some("rustfs-oidc")
         && claims
@@ -2377,6 +2665,86 @@ mod tests {
         assert!(disabled_allowed);
     }
 
+    #[tokio::test]
+    #[serial]
+    async fn opa_cannot_authorize_disabled_parents_of_derived_credentials() {
+        let iam = IamSys::new(IamCache::new(StsTestMockStore::new(false)).await.expect("initialize IAM"));
+        let previous = IamSys::<StsTestMockStore>::policy_plugin_state().await;
+        IamSys::<StsTestMockStore>::set_policy_plugin_client(opa::AuthZPlugin::new(opa::Args {
+            url: "http://127.0.0.1:1/allow".to_string(),
+            auth_token: String::new(),
+        }))
+        .await;
+        let mut outcomes = Vec::new();
+        for (service_account, spoofed_oidc_claims) in [(false, false), (true, false), (true, true)] {
+            let parent = "opa-disabled-parent";
+            let account = if service_account {
+                "opa-service-child"
+            } else {
+                "opa-session-child"
+            };
+            let mut parent_identity = UserIdentity::new(Credentials {
+                access_key: parent.to_string(),
+                secret_key: "parent-secret".to_string(),
+                status: ACCOUNT_ON.to_string(),
+                ..Default::default()
+            });
+            let mut claims = HashMap::from([("parent".to_string(), Value::String(parent.to_string()))]);
+            if service_account {
+                claims.insert(iam_policy_claim_name_sa(), Value::String(INHERITED_POLICY_TYPE.to_string()));
+            }
+            if spoofed_oidc_claims {
+                claims.extend([
+                    ("iss".to_string(), Value::String("rustfs-oidc".to_string())),
+                    ("oidc_provider".to_string(), Value::String("custom-provider".to_string())),
+                    ("sub".to_string(), Value::String("custom-subject".to_string())),
+                ]);
+            }
+            let child = UserIdentity::new(Credentials {
+                access_key: account.to_string(),
+                secret_key: "child-secret".to_string(),
+                session_token: "signed-session".to_string(),
+                parent_user: parent.to_string(),
+                status: ACCOUNT_ON.to_string(),
+                claims: Some(claims.clone()),
+                ..Default::default()
+            });
+            iam.store.cache.add_or_update_user(account, &child, OffsetDateTime::now_utc());
+            let conditions = HashMap::new();
+            let args = Args {
+                account,
+                groups: &None,
+                action: Action::S3Action(S3Action::GetObjectAction),
+                bucket: "bucket",
+                object: "object",
+                conditions: &conditions,
+                claims: &claims,
+                is_owner: false,
+                deny_only: false,
+            };
+            for enabled in [true, false, true] {
+                parent_identity.credentials.status = if enabled { "on" } else { "off" }.to_string();
+                iam.store
+                    .cache
+                    .add_or_update_user(parent, &parent_identity, OffsetDateTime::now_utc());
+                let prepared = iam.prepare_auth(&args).await;
+                let correct = if enabled {
+                    matches!(prepared.mode, PreparedIamMode::Opa)
+                } else {
+                    matches!(iam.try_eval_prepared(&prepared, &args).await, Err(Error::IAMActionNotAllowed))
+                };
+                outcomes.push((service_account, spoofed_oidc_claims, enabled, correct));
+            }
+        }
+        *get_policy_plugin_state().write().await = previous;
+        for (service_account, spoofed_oidc_claims, enabled, correct) in outcomes {
+            assert!(
+                correct,
+                "service_account={service_account}, spoofed_oidc_claims={spoofed_oidc_claims}, parent_enabled={enabled}"
+            );
+        }
+    }
+
     #[tokio::test]
     #[serial]
     async fn test_prepare_auth_requests_existing_object_tags_in_opa_mode() {
@@ -2542,7 +2910,7 @@ mod tests {
         let url = format!("http://{}/decision", listener.local_addr().expect("receiver address"));
         let receiver = tokio::spawn(async move {
             let mut payloads = Vec::new();
-            for _ in 0..5 {
+            for decision_index in 0..7 {
                 let (stream, _) = listener.accept().await.expect("accept OPA request");
                 let mut stream = BufReader::new(stream);
                 let mut length = None;
@@ -2561,11 +2929,16 @@ mod tests {
                 let mut body = vec![0; length.expect("OPA JSON has a content length")];
                 stream.read_exact(&mut body).await.expect("read complete OPA body");
                 payloads.push(serde_json::from_slice::<serde_json::Value>(&body).expect("OPA JSON"));
-                stream
-                    .get_mut()
-                    .write_all(b"HTTP/1.1 200 OK\r\nContent-Length: 15\r\nConnection: close\r\n\r\n{\"result\":true}")
-                    .await
-                    .expect("send decision");
+                let decision = if decision_index == 6 {
+                    "{\"result\":false}"
+                } else {
+                    "{\"result\":true}"
+                };
+                let response = format!(
+                    "HTTP/1.1 200 OK\r\nContent-Length: {}\r\nConnection: close\r\n\r\n{decision}",
+                    decision.len()
+                );
+                stream.get_mut().write_all(response.as_bytes()).await.expect("send decision");
             }
             payloads
         });
@@ -2632,12 +3005,31 @@ mod tests {
                 let prepared = iam.prepare_auth(&args).await;
                 let error = iam.try_eval_prepared(&prepared, &args).await;
                 let denied = !iam.eval_prepared(&prepared, &args).await;
+                args.action = Action::S3Action(S3Action::PutBucketTaggingAction);
+                assert!(
+                    !with_bucket_tag_deletion(iam.is_allowed(&args)).await,
+                    "storage failures must still prevent tag deletion"
+                );
+                for _ in 0..2 {
+                    *store.bucket_tags.lock().expect("tag state") =
+                        Err(Error::from(crate::IamStorageError::other(crate::storage_api::UnreadableBucketConfig {
+                            bucket: args.bucket.to_owned(),
+                            config_file: "tagging.xml".to_owned(),
+                            raw_len: 42,
+                        })));
+                    assert!(!iam.is_allowed(&args).await, "ordinary PutBucketTagging must not bypass unreadable tags");
+                    outcomes.push(with_bucket_tag_deletion(iam.is_allowed(&args)).await);
+                }
                 *get_policy_plugin_state().write().await = previous;
                 (outcomes, error, denied)
             },
         )
         .await;
-        assert_eq!(outcomes, [true; 5]);
+        assert_eq!(
+            outcomes,
+            [true, true, true, true, true, true, false],
+            "OPA must still authorize deletion of unreadable tags"
+        );
         assert!(
             matches!(error, Err(Error::Io(_))),
             "lookup failure must remain an error, not an implicit denial"
@@ -2684,6 +3076,12 @@ mod tests {
         block_delete: Arc<std::sync::atomic::AtomicBool>,
         delete_started: Arc<tokio::sync::Notify>,
         release_delete: Arc<tokio::sync::Notify>,
+        block_regular_save: Arc<std::sync::atomic::AtomicBool>,
+        regular_save_started: Arc<tokio::sync::Notify>,
+        release_regular_save: Arc<tokio::sync::Notify>,
+        block_derived_save: Arc<std::sync::atomic::AtomicBool>,
+        derived_save_started: Arc<tokio::sync::Notify>,
+        release_derived_save: Arc<tokio::sync::Notify>,
         block_group_save: Arc<std::sync::atomic::AtomicBool>,
         group_save_started: Arc<tokio::sync::Notify>,
         group_save_release: Arc<tokio::sync::Notify>,
@@ -2701,6 +3099,12 @@ mod tests {
                 block_delete: Arc::new(std::sync::atomic::AtomicBool::new(false)),
                 delete_started: Arc::new(tokio::sync::Notify::new()),
                 release_delete: Arc::new(tokio::sync::Notify::new()),
+                block_regular_save: Arc::new(std::sync::atomic::AtomicBool::new(false)),
+                regular_save_started: Arc::new(tokio::sync::Notify::new()),
+                release_regular_save: Arc::new(tokio::sync::Notify::new()),
+                block_derived_save: Arc::new(std::sync::atomic::AtomicBool::new(false)),
+                derived_save_started: Arc::new(tokio::sync::Notify::new()),
+                release_derived_save: Arc::new(tokio::sync::Notify::new()),
                 block_group_save: Arc::new(std::sync::atomic::AtomicBool::new(false)),
                 group_save_started: Arc::new(tokio::sync::Notify::new()),
                 group_save_release: Arc::new(tokio::sync::Notify::new()),
@@ -2717,8 +3121,20 @@ mod tests {
 
     #[async_trait::async_trait]
     impl Store for StsTestMockStore {
-        async fn load_bucket_tags(&self, _bucket: &str) -> Result<HashMap<String, String>> {
-            self.bucket_tags.lock().expect("tag state").clone()
+        async fn load_bucket_tags(&self, bucket: &str) -> Result<HashMap<String, String>> {
+            let tags = self.bucket_tags.lock().expect("tag state");
+            // Error::clone stringifies IO errors; retain the typed storage refusal
+            // so this fixture exercises the same recovery decision as ObjectStore.
+            if tags.as_ref().is_err_and(crate::storage_api::is_unreadable_bucket_tags) {
+                return Err(Error::from(crate::storage_api::IamStorageError::other(
+                    crate::storage_api::UnreadableBucketConfig {
+                        bucket: bucket.to_string(),
+                        config_file: "tagging.xml".to_string(),
+                        raw_len: 42,
+                    },
+                )));
+            }
+            tags.clone()
         }
 
         fn has_watcher(&self) -> bool {
@@ -2744,6 +3160,16 @@ mod tests {
             item: UserIdentity,
             _ttl: Option<usize>,
         ) -> Result<()> {
+            if user_type == UserType::Reg && self.block_regular_save.load(std::sync::atomic::Ordering::SeqCst) {
+                self.regular_save_started.notify_one();
+                self.release_regular_save.notified().await;
+            }
+            if matches!(user_type, UserType::Svc | UserType::Sts)
+                && self.block_derived_save.load(std::sync::atomic::Ordering::SeqCst)
+            {
+                self.derived_save_started.notify_one();
+                self.release_derived_save.notified().await;
+            }
             if user_type == UserType::Svc {
                 *self
                     .saved_service_account_count
@@ -2799,6 +3225,18 @@ mod tests {
                 });
                 m.insert(name.to_string(), user);
             }
+            if let Some(user) = self.saved_sts_users.lock().expect("saved users").get(name) {
+                let stored_type = if user.credentials.is_service_account() {
+                    UserType::Svc
+                } else if !user.credentials.session_token.is_empty() {
+                    UserType::Sts
+                } else {
+                    UserType::Reg
+                };
+                if user_type == stored_type {
+                    m.insert(name.to_string(), user.clone());
+                }
+            }
             Ok(())
         }
 
@@ -2903,6 +3341,20 @@ mod tests {
                 Policy::parse_config(CUSTOM_STS_CLAIM_POLICY_JSON.as_bytes()).expect("custom STS claim policy should parse");
             policy_docs.insert(CUSTOM_STS_CLAIM_POLICY.to_string(), PolicyDoc::new(custom_claim_policy));
 
+            // Background reloads must observe the identities this mock persisted.
+            // Keep the mock storage lock through publication, just as its writes
+            // are serialized, instead of resetting live identities to seed data.
+            let saved = self.saved_sts_users.lock().expect("saved users");
+            let mut saved_users = HashMap::new();
+            let mut saved_sessions = HashMap::new();
+            for (key, identity) in saved.iter() {
+                if !identity.credentials.session_token.is_empty() && !identity.credentials.is_service_account() {
+                    saved_sessions.insert(key.clone(), identity.clone());
+                } else {
+                    saved_users.insert(key.clone(), identity.clone());
+                }
+            }
+
             if self.empty_policies {
                 const PARENT_USER: &str = "sts-empty-parent-policy-test";
                 let creds = Credentials {
@@ -2924,6 +3376,7 @@ mod tests {
                 };
                 let mut users = HashMap::new();
                 users.insert(PARENT_USER.to_string(), parent_identity);
+                users.extend(saved_users);
 
                 cache.with_write_lock(|cache| {
                     cache.replace_policy_docs(CacheEntity::new(policy_docs));
@@ -2931,7 +3384,7 @@ mod tests {
                     cache.replace_groups(CacheEntity::default());
                     cache.replace_group_policies(CacheEntity::default());
                     cache.replace_user_policies(CacheEntity::default());
-                    cache.replace_sts_accounts(CacheEntity::default());
+                    cache.replace_sts_accounts(CacheEntity::new(saved_sessions));
                     cache.replace_sts_policies(CacheEntity::default());
                     cache.build_user_group_memberships();
                 });
@@ -2960,6 +3413,7 @@ mod tests {
             };
             let mut users = HashMap::new();
             users.insert(PARENT_USER.to_string(), parent_identity);
+            users.extend(saved_users);
 
             let group = GroupInfo::new(vec![PARENT_USER.to_string()]);
             let mut groups = HashMap::new();
@@ -2975,7 +3429,7 @@ mod tests {
                 cache.replace_groups(CacheEntity::new(groups));
                 cache.replace_group_policies(CacheEntity::new(group_policies));
                 cache.replace_user_policies(CacheEntity::default());
-                cache.replace_sts_accounts(CacheEntity::default());
+                cache.replace_sts_accounts(CacheEntity::new(saved_sessions));
                 cache.replace_sts_policies(CacheEntity::default());
                 cache.build_user_group_memberships();
             });
@@ -3309,6 +3763,547 @@ mod tests {
         assert_eq!(err, Error::AccessKeyAlreadyExists);
     }
 
+    #[tokio::test]
+    async fn service_account_creation_rejects_invalid_path_components_before_storage() {
+        ensure_test_global_credentials();
+        let iam_sys = test_iam_sys().await;
+        for key in [
+            "nul\0key",
+            "slash/key",
+            "back\\slash",
+            ".",
+            "..",
+            " . ",
+            "line\nkey",
+            "del\u{7f}key",
+            "c1\u{85}key",
+        ] {
+            let error = iam_sys
+                .new_service_account("svc-parent-user", None, service_account_opts(key, "serviceAccountSecret123"))
+                .await
+                .expect_err("invalid access keys must not reach persistent storage");
+            assert_eq!(error, Error::InvalidArgument, "{key:?}");
+        }
+        assert_eq!(iam_sys.store.api.saved_service_account_count(), 0);
+        iam_sys
+            .new_service_account("svc-parent-user", None, service_account_opts("valid-svc-key", "serviceAccountSecret123"))
+            .await
+            .expect("a valid service account remains creatable after rejected keys");
+        assert_eq!(iam_sys.store.api.saved_service_account_count(), 1);
+    }
+
+    #[tokio::test]
+    async fn temporary_account_lookup_rejects_service_account_credentials() {
+        ensure_test_global_credentials();
+        let iam_sys = test_iam_sys().await;
+        let mut opts = service_account_opts("expiring-service-key", "serviceAccountSecret123");
+        opts.expiration = Some(OffsetDateTime::now_utc() + time::Duration::hours(1));
+        let (created, _) = iam_sys
+            .new_service_account("svc-parent-user", None, opts)
+            .await
+            .expect("create an expiring service account");
+        assert!(created.is_temp(), "session-token shape alone cannot distinguish service accounts");
+        let error = iam_sys
+            .get_temporary_account(&created.access_key)
+            .await
+            .expect_err("temporary-account permission must not expose service accounts");
+        assert!(matches!(error, Error::NoSuchTempAccount(_)));
+        let (service, _) = iam_sys
+            .get_service_account(&created.access_key)
+            .await
+            .expect("service-account lookup remains available");
+        assert_eq!(service.access_key, created.access_key);
+    }
+
+    fn rotation_test_session(parent: &str, key: &str) -> Credentials {
+        Credentials {
+            access_key: key.to_string(),
+            secret_key: "derivedSessionSecret123".to_string(),
+            session_token: "signed-session".to_string(),
+            expiration: Some(OffsetDateTime::now_utc() + time::Duration::hours(1)),
+            status: ACCOUNT_ON.to_string(),
+            parent_user: parent.to_string(),
+            ..Default::default()
+        }
+    }
+
+    #[tokio::test]
+    async fn add_user_rejects_active_and_expired_derived_access_keys() {
+        let iam = test_iam_sys().await;
+        let args = AddOrUpdateUserReq {
+            secret_key: "replacementSecret123".to_string(),
+            policy: None,
+            status: rustfs_madmin::AccountStatus::Enabled,
+        };
+        for service in [false, true] {
+            for expired in [false, true] {
+                let key = format!("collision-{service}-{expired}");
+                let mut child = rotation_test_session("existing-parent", &key);
+                if expired {
+                    child.expiration = Some(OffsetDateTime::UNIX_EPOCH);
+                }
+                if service {
+                    child.claims = Some(HashMap::from([(
+                        iam_policy_claim_name_sa(),
+                        Value::String(INHERITED_POLICY_TYPE.to_string()),
+                    )]));
+                }
+                // This fixture represents a persisted identity. The immediate
+                // background reload must not erase a cache-only insertion.
+                iam.store
+                    .api
+                    .save_user_identity(
+                        &key,
+                        if service { UserType::Svc } else { UserType::Sts },
+                        UserIdentity::new(child.clone()),
+                        None,
+                    )
+                    .await
+                    .expect("persist derived identity");
+                if service {
+                    iam.store
+                        .cache
+                        .add_or_update_user(&key, &UserIdentity::new(child.clone()), OffsetDateTime::now_utc());
+                } else {
+                    iam.store
+                        .cache
+                        .add_or_update_sts_account(&key, &UserIdentity::new(child.clone()), OffsetDateTime::now_utc());
+                }
+                assert_eq!(
+                    iam.create_user(&key, &args).await.expect_err("reject derived key"),
+                    Error::AccessKeyAlreadyExists
+                );
+                assert_eq!(
+                    iam.get_user(&key).await.expect("preserved identity").credentials.secret_key,
+                    child.secret_key
+                );
+                assert_eq!(
+                    iam.store
+                        .api
+                        .saved_sts_users
+                        .lock()
+                        .expect("saved users")
+                        .get(&key)
+                        .expect("preserved persistent identity")
+                        .credentials
+                        .secret_key,
+                    child.secret_key,
+                    "a rejected collision must not overwrite the persisted derived identity"
+                );
+            }
+        }
+        iam.create_user("regular-update", &args).await.expect("create regular user");
+        iam.create_user("regular-update", &args)
+            .await
+            .expect("regular user update remains supported");
+    }
+
+    #[tokio::test]
+    async fn add_user_secret_rotation_revokes_sessions_but_identical_secret_does_not() {
+        let iam = test_iam_sys().await;
+        let parent = "rotation-parent";
+        let mut args = AddOrUpdateUserReq {
+            secret_key: "originalParentSecret123".to_string(),
+            policy: None,
+            status: rustfs_madmin::AccountStatus::Enabled,
+        };
+        iam.create_user(parent, &args).await.expect("create parent");
+        let authenticated = iam.get_user(parent).await.expect("parent").credentials;
+        let child = rotation_test_session(parent, "rotation-session");
+        iam.set_temp_user_from_parent(&child, &authenticated)
+            .await
+            .expect("mint session");
+        iam.create_user(parent, &args).await.expect("same secret is idempotent");
+        assert!(iam.get_user(&child.access_key).await.is_some());
+        args.secret_key = "replacementParentSecret123".to_string();
+        let probe = IamSys::<StsTestMockStore>::load_user_notification_probe(0, false, false);
+        crate::LOAD_USER_NOTIFICATION_PROBE
+            .scope(probe, iam.create_user(parent, &args))
+            .await
+            .expect("rotate via add-user");
+        assert!(iam.get_user(&child.access_key).await.is_none());
+        assert!(
+            !iam.store
+                .api
+                .saved_sts_users
+                .lock()
+                .expect("saved users")
+                .contains_key(&child.access_key)
+        );
+        assert!(matches!(
+            iam.set_temp_user_from_parent(&child, &authenticated).await,
+            Err(Error::IAMActionNotAllowed)
+        ));
+    }
+
+    #[tokio::test]
+    async fn self_secret_change_cannot_undo_concurrent_disable_rotation_or_deletion() {
+        ensure_test_global_credentials();
+        for mutation in ["disable", "rotate", "delete"] {
+            let store = StsTestMockStore::new(false);
+            let iam = Arc::new(IamSys::new(IamCache::new(store.clone()).await.expect("IAM")));
+            let parent = "self-change-parent";
+            let original = "originalParentSecret123";
+            iam.create_user(
+                parent,
+                &AddOrUpdateUserReq {
+                    secret_key: original.to_string(),
+                    policy: None,
+                    status: rustfs_madmin::AccountStatus::Enabled,
+                },
+            )
+            .await
+            .expect("create parent");
+            if mutation == "delete" {
+                store.block_delete.store(true, std::sync::atomic::Ordering::SeqCst);
+            } else {
+                store.block_regular_save.store(true, std::sync::atomic::Ordering::SeqCst);
+            }
+            let administrator = {
+                let iam = Arc::clone(&iam);
+                tokio::spawn(async move {
+                    match mutation {
+                        "delete" => iam.delete_user(parent, false).await,
+                        "disable" => iam
+                            .set_user_status(parent, rustfs_madmin::AccountStatus::Disabled)
+                            .await
+                            .map(|_| ()),
+                        _ => iam.rotate_user_secret_key(parent, "administratorSecret123").await.map(|_| ()),
+                    }
+                })
+            };
+            let started = if mutation == "delete" {
+                &store.delete_started
+            } else {
+                &store.regular_save_started
+            };
+            tokio::time::timeout(std::time::Duration::from_secs(5), started.notified())
+                .await
+                .expect("admin storage barrier");
+            let stale_self = {
+                let iam = Arc::clone(&iam);
+                tokio::spawn(async move { iam.change_own_secret_key(parent, original, "attackerChosenSecret123").await })
+            };
+            assert!(iam.store.cache.parent_mutation_lock(parent).try_lock().is_err());
+            store.block_delete.store(false, std::sync::atomic::Ordering::SeqCst);
+            store.block_regular_save.store(false, std::sync::atomic::Ordering::SeqCst);
+            if mutation == "delete" {
+                store.release_delete.notify_one();
+            } else {
+                store.release_regular_save.notify_one();
+            }
+            tokio::time::timeout(std::time::Duration::from_secs(5), administrator)
+                .await
+                .expect("admin finishes")
+                .expect("admin join")
+                .expect("admin mutation");
+            let error = tokio::time::timeout(std::time::Duration::from_secs(5), stale_self)
+                .await
+                .expect("self finishes")
+                .expect("self join")
+                .expect_err("stale self change must fail");
+            assert_eq!(error, Error::IAMActionNotAllowed);
+            let cached = iam.store.get_user(parent).await;
+            let persisted = store.saved_sts_users.lock().expect("saved users").get(parent).cloned();
+            for identity in [cached, persisted] {
+                match mutation {
+                    "delete" => assert!(identity.is_none(), "self request must not resurrect a removed identity"),
+                    "disable" => {
+                        let cred = identity.expect("disabled identity").credentials;
+                        assert!(!cred.is_valid());
+                        assert_eq!(cred.secret_key, original);
+                    }
+                    _ => assert_eq!(identity.expect("rotated identity").credentials.secret_key, "administratorSecret123"),
+                }
+            }
+        }
+        let iam = test_iam_sys().await;
+        iam.create_user(
+            "self-positive",
+            &AddOrUpdateUserReq {
+                secret_key: "originalParentSecret123".to_string(),
+                policy: None,
+                status: rustfs_madmin::AccountStatus::Enabled,
+            },
+        )
+        .await
+        .expect("create parent");
+        let (_, status, _) = iam
+            .change_own_secret_key("self-positive", "originalParentSecret123", "replacementParentSecret123")
+            .await
+            .expect("current enabled caller may rotate");
+        assert_eq!(status, rustfs_madmin::AccountStatus::Enabled);
+        assert_eq!(
+            iam.get_user("self-positive")
+                .await
+                .expect("updated user")
+                .credentials
+                .secret_key,
+            "replacementParentSecret123"
+        );
+    }
+
+    #[tokio::test]
+    async fn secret_rotation_and_add_user_finish_revocation_after_caller_cancellation() {
+        ensure_test_global_credentials();
+        for via_add_user in [false, true] {
+            let store = StsTestMockStore::new(false);
+            let iam = Arc::new(IamSys::new(IamCache::new(store.clone()).await.expect("IAM")));
+            let parent = "cancel-rotation-parent";
+            let mut args = AddOrUpdateUserReq {
+                secret_key: "originalParentSecret123".to_string(),
+                policy: None,
+                status: rustfs_madmin::AccountStatus::Enabled,
+            };
+            iam.create_user(parent, &args).await.expect("create parent");
+            let authenticated = iam.get_user(parent).await.expect("parent").credentials;
+            let session = rotation_test_session(parent, "cancel-rotation-session");
+            iam.set_temp_user_from_parent(&session, &authenticated)
+                .await
+                .expect("mint session");
+            args.secret_key = "replacementParentSecret123".to_string();
+            store.block_delete.store(true, std::sync::atomic::Ordering::SeqCst);
+            let rotation = {
+                let iam = Arc::clone(&iam);
+                tokio::spawn(async move {
+                    let probe = IamSys::<StsTestMockStore>::load_user_notification_probe(0, false, false);
+                    crate::LOAD_USER_NOTIFICATION_PROBE
+                        .scope(probe, async {
+                            if via_add_user {
+                                iam.create_user(parent, &args).await.map(|_| ())
+                            } else {
+                                iam.rotate_user_secret_key(parent, &args.secret_key).await.map(|_| ())
+                            }
+                        })
+                        .await
+                })
+            };
+            tokio::time::timeout(std::time::Duration::from_secs(5), store.delete_started.notified())
+                .await
+                .expect("rotation reached revocation");
+            rotation.abort();
+            assert!(rotation.await.expect_err("caller canceled").is_cancelled());
+            assert!(
+                iam.store.cache.parent_mutation_lock(parent).try_lock().is_err(),
+                "canceling the caller must not release the rotation lock"
+            );
+            store.block_delete.store(false, std::sync::atomic::Ordering::SeqCst);
+            store.release_delete.notify_one();
+            let parent_lock = iam.store.cache.parent_mutation_lock(parent);
+            let completed = tokio::time::timeout(std::time::Duration::from_secs(5), parent_lock.lock())
+                .await
+                .expect("rotation must complete its sweep");
+            assert!(iam.store.get_user(&session.access_key).await.is_none());
+            assert!(
+                !store
+                    .saved_sts_users
+                    .lock()
+                    .expect("saved users")
+                    .contains_key(&session.access_key)
+            );
+            assert_eq!(
+                iam.store.get_user(parent).await.expect("parent").credentials.secret_key,
+                "replacementParentSecret123"
+            );
+            drop(completed);
+            assert!(matches!(
+                iam.set_temp_user_from_parent(&session, &authenticated).await,
+                Err(Error::IAMActionNotAllowed)
+            ));
+        }
+    }
+
+    #[tokio::test]
+    async fn revoked_sts_cannot_mint_service_account_between_rotation_and_sweep() {
+        ensure_test_global_credentials();
+        let store = StsTestMockStore::new(false);
+        let iam = Arc::new(IamSys::new(IamCache::new(store.clone()).await.expect("IAM")));
+        let parent = "sts-rotation-parent";
+        iam.create_user(
+            parent,
+            &AddOrUpdateUserReq {
+                secret_key: "originalParentSecret123".to_string(),
+                policy: None,
+                status: rustfs_madmin::AccountStatus::Enabled,
+            },
+        )
+        .await
+        .expect("create parent");
+        let original_parent = iam.get_user(parent).await.expect("parent").credentials;
+        let session = rotation_test_session(parent, "sts-rotation-session");
+        iam.set_temp_user_from_parent(&session, &original_parent)
+            .await
+            .expect("mint STS");
+        store.block_delete.store(true, std::sync::atomic::Ordering::SeqCst);
+        let rotation = {
+            let iam = Arc::clone(&iam);
+            tokio::spawn(async move {
+                let probe = IamSys::<StsTestMockStore>::load_user_notification_probe(0, false, false);
+                crate::LOAD_USER_NOTIFICATION_PROBE
+                    .scope(probe, iam.rotate_user_secret_key(parent, "replacementParentSecret123"))
+                    .await
+            })
+        };
+        tokio::time::timeout(std::time::Duration::from_secs(5), store.delete_started.notified())
+            .await
+            .expect("sweep reached storage");
+        assert!(
+            iam.store.cache.parent_mutation_lock(parent).try_lock().is_err(),
+            "rotation must retain its lock through the sweep"
+        );
+        let creation = {
+            let iam = Arc::clone(&iam);
+            tokio::spawn(async move {
+                iam.new_service_account_from_caller(
+                    parent,
+                    None,
+                    service_account_opts("escaped-service", "escapedServiceSecret123"),
+                    &session,
+                )
+                .await
+            })
+        };
+        store.block_delete.store(false, std::sync::atomic::Ordering::SeqCst);
+        store.release_delete.notify_one();
+        let (_, _, revoked) = tokio::time::timeout(std::time::Duration::from_secs(5), rotation)
+            .await
+            .expect("rotation timeout")
+            .expect("rotation join")
+            .expect("rotation");
+        assert_eq!(revoked, 1);
+        let result = tokio::time::timeout(std::time::Duration::from_secs(5), creation)
+            .await
+            .expect("creation timeout")
+            .expect("creation join");
+        assert!(matches!(result, Err(Error::IAMActionNotAllowed)));
+        assert!(
+            !store
+                .saved_sts_users
+                .lock()
+                .expect("saved users")
+                .contains_key("escaped-service")
+        );
+    }
+
+    #[tokio::test]
+    async fn derived_publication_is_ordered_with_parent_rotation_and_deletion() {
+        ensure_test_global_credentials();
+        for service in [false, true] {
+            for (deleting, canceled) in [(false, false), (true, false), (false, true), (true, true)] {
+                let store = StsTestMockStore::new(false);
+                let iam = Arc::new(IamSys::new(IamCache::new(store.clone()).await.expect("IAM")));
+                let parent = "concurrent-parent";
+                iam.create_user(
+                    parent,
+                    &AddOrUpdateUserReq {
+                        secret_key: "originalParentSecret123".to_string(),
+                        policy: None,
+                        status: rustfs_madmin::AccountStatus::Enabled,
+                    },
+                )
+                .await
+                .expect("create parent");
+                let authenticated = iam.get_user(parent).await.expect("parent").credentials;
+                let key = "concurrent-derived-key";
+                store.block_derived_save.store(true, std::sync::atomic::Ordering::SeqCst);
+                let creation = {
+                    let iam = Arc::clone(&iam);
+                    let authenticated = authenticated.clone();
+                    tokio::spawn(async move {
+                        if service {
+                            iam.new_service_account_from_caller(
+                                parent,
+                                None,
+                                service_account_opts(key, "derivedServiceSecret123"),
+                                &authenticated,
+                            )
+                            .await
+                            .map(|_| ())
+                        } else {
+                            iam.set_temp_user_from_parent(&rotation_test_session(parent, key), &authenticated)
+                                .await
+                                .map(|_| ())
+                        }
+                    })
+                };
+                tokio::time::timeout(std::time::Duration::from_secs(5), store.derived_save_started.notified())
+                    .await
+                    .expect("creation reached storage");
+                let creation = if canceled {
+                    creation.abort();
+                    assert!(creation.await.expect_err("caller canceled").is_cancelled());
+                    None
+                } else {
+                    Some(creation)
+                };
+                let parent_lock = iam.store.cache.parent_mutation_lock(parent);
+                assert!(parent_lock.try_lock().is_err(), "publication must own the parent's mutation boundary");
+                let mutation = {
+                    let iam = Arc::clone(&iam);
+                    tokio::spawn(async move {
+                        if deleting {
+                            iam.delete_user(parent, false).await
+                        } else {
+                            let probe = IamSys::<StsTestMockStore>::load_user_notification_probe(0, false, false);
+                            crate::LOAD_USER_NOTIFICATION_PROBE
+                                .scope(probe, iam.set_user_secret_key(parent, "replacementParentSecret123"))
+                                .await
+                                .map(|_| ())
+                        }
+                    })
+                };
+                store.block_derived_save.store(false, std::sync::atomic::Ordering::SeqCst);
+                store.release_derived_save.notify_one();
+                if let Some(creation) = creation {
+                    tokio::time::timeout(std::time::Duration::from_secs(5), creation)
+                        .await
+                        .expect("creation timeout")
+                        .expect("creation join")
+                        .expect("creation");
+                }
+                tokio::time::timeout(std::time::Duration::from_secs(5), mutation)
+                    .await
+                    .expect("mutation timeout")
+                    .expect("mutation join")
+                    .expect("mutation");
+                assert_eq!(
+                    iam.get_user(key).await.is_some(),
+                    service && !deleting,
+                    "existing service keys survive rotation, but no derived keys survive parent deletion"
+                );
+                assert!(matches!(
+                    iam.set_temp_user_from_parent(&rotation_test_session(parent, "late-session"), &authenticated)
+                        .await,
+                    Err(Error::IAMActionNotAllowed)
+                ));
+                assert!(matches!(
+                    iam.new_service_account_from_caller(
+                        parent,
+                        None,
+                        service_account_opts("late-service", "lateServiceSecret123"),
+                        &authenticated
+                    )
+                    .await,
+                    Err(Error::IAMActionNotAllowed)
+                ));
+                assert!(
+                    !store
+                        .saved_sts_users
+                        .lock()
+                        .expect("saved users")
+                        .contains_key("late-session")
+                );
+                assert!(
+                    !store
+                        .saved_sts_users
+                        .lock()
+                        .expect("saved users")
+                        .contains_key("late-service")
+                );
+            }
+        }
+    }
+
     #[tokio::test]
     async fn service_account_creation_rejects_regular_user_access_key() {
         ensure_test_global_credentials();
diff --git a/rustfs/src/admin/auth.rs b/rustfs/src/admin/auth.rs
index edcc03101..685fa13c9 100644
--- a/rustfs/src/admin/auth.rs
+++ b/rustfs/src/admin/auth.rs
@@ -293,6 +293,18 @@ pub async fn authenticate_request(
     result
 }
 
+/// The policy client address comes only from verified middleware context.
+/// Keep the original socket peer in request extensions for auditing.
+pub(crate) fn policy_source_addr(extensions: &http::Extensions) -> Option<std::net::SocketAddr> {
+    let peer = extensions
+        .get::<Option<RemoteAddr>>()
+        .and_then(|peer| peer.map(|addr| addr.0));
+    extensions
+        .get::<rustfs_trusted_proxies::ClientInfo>()
+        .map(|client| std::net::SocketAddr::new(client.real_ip, peer.map_or(0, |addr| addr.port())))
+        .or(peer)
+}
+
 /// Full admin gate over an `S3Request`: extract the request credentials,
 /// authenticate them ([`authenticate_request`]), then authorize the caller for
 /// `actions` ([`validate_admin_request`], allowing on the first permitted
@@ -306,7 +318,7 @@ pub async fn authorize_admin_request(req: &S3Request<Body>, actions: Vec<Action>
 
     let (cred, owner) = authenticate_request(&req.headers, &req.uri, input_cred).await?;
 
-    let remote_addr = req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0));
+    let remote_addr = policy_source_addr(&req.extensions);
     validate_admin_request(&req.headers, &cred, owner, false, actions, remote_addr).await?;
 
     Ok(cred)
@@ -547,6 +559,163 @@ mod tests {
         );
     }
 
+    #[test]
+    #[serial_test::serial]
+    fn admin_and_sts_handlers_use_verified_client_ip_and_bucket_scope() {
+        crate::app::gating_test_env::run_large_stack_test("admin-client-conditions", || async {
+            use crate::admin::router::Operation;
+            use crate::admin::runtime_sources::{AppContext, IamInterface, KmsInterface, publish_test_app_context};
+            use rustfs_iam::store::object::ObjectStore;
+            use rustfs_madmin::{AccountStatus, AddOrUpdateUserReq};
+            use std::sync::Arc;
+            struct ReadyIam(Arc<rustfs_iam::sys::IamSys<ObjectStore>>);
+            impl IamInterface for ReadyIam {
+                fn handle(&self) -> Arc<rustfs_iam::sys::IamSys<ObjectStore>> {
+                    self.0.clone()
+                }
+                fn is_ready(&self) -> bool {
+                    true
+                }
+            }
+            struct TestKms;
+            impl KmsInterface for TestKms {
+                fn handle(&self) -> Arc<rustfs_kms::KmsServiceManager> {
+                    Arc::new(rustfs_kms::KmsServiceManager::new())
+                }
+            }
+            let previous = crate::runtime_sources::current_app_context();
+            let (_directory, _paths, store) = crate::app::gating_test_env::isolated_multi_pool_ecstore().await;
+            ObjectStore::new(store.clone())
+                .save_iam_config(
+                    serde_json::json!({"version": 1}),
+                    format!("{}/format.json", *rustfs_iam::store::object::IAM_CONFIG_PREFIX),
+                )
+                .await
+                .unwrap();
+            let iam = rustfs_iam::build_iam_sys(store.clone()).await.unwrap();
+            for (key, document) in [
+                (
+                    "proxy-admin",
+                    serde_json::json!({"Version":"2012-10-17","Statement":[
+                        {"Effect":"Allow","Action":"admin:*"},
+                        {"Effect":"Allow","Action":"sts:AssumeRole"},
+                        {"Effect":"Deny","Action":"admin:*","Condition":{"NotIpAddress":{"aws:SourceIp":"10.0.0.0/8"}}},
+                        {"Effect":"Deny","Action":"sts:AssumeRole","Condition":{"NotIpAddress":{"aws:SourceIp":"10.0.0.0/8"}}}
+                    ]}),
+                ),
+                (
+                    "scoped-usage",
+                    serde_json::json!({"Version":"2012-10-17","Statement":[
+                        {"Effect":"Allow","Action":"s3:ListBucket","Resource":"arn:aws:s3:::usage-allowed"},
+                        {"Effect":"Deny","Action":"s3:ListBucket","NotResource":"arn:aws:s3:::usage-allowed"}
+                    ]}),
+                ),
+            ] {
+                iam.create_user(
+                    key,
+                    &AddOrUpdateUserReq {
+                        secret_key: "test-user-secret".to_owned(),
+                        policy: None,
+                        status: AccountStatus::Enabled,
+                    },
+                )
+                .await
+                .unwrap();
+                iam.set_policy(key, Policy::parse_config(&serde_json::to_vec(&document).unwrap()).unwrap())
+                    .await
+                    .unwrap();
+                iam.policy_db_set(key, UserType::Reg, false, key).await.unwrap();
+            }
+            let context = Arc::new(AppContext::new(store, Arc::new(ReadyIam(iam)), Arc::new(TestKms)));
+            assert!(context.publish_action_credentials(rustfs_credentials::Credentials {
+                access_key: "proxy-test-root".to_owned(),
+                secret_key: "proxy-root-secret".to_owned(),
+                status: "on".to_owned(),
+                ..Default::default()
+            }));
+            publish_test_app_context(context);
+            let request = |key: &str, client_ip: Option<&str>| {
+                let mut extensions = http::Extensions::new();
+                extensions.insert(Some(RemoteAddr("10.1.2.3:4567".parse().unwrap())));
+                if let Some(ip) = client_ip {
+                    extensions.insert(rustfs_trusted_proxies::ClientInfo::direct(format!("{ip}:7890").parse().unwrap()));
+                }
+                let mut headers = HeaderMap::new();
+                headers.insert("x-forwarded-for", "10.1.2.3".parse().unwrap());
+                headers.insert("x-real-ip", "10.1.2.3".parse().unwrap());
+                S3Request {
+                    input: Body::from(String::new()),
+                    method: http::Method::GET,
+                    uri: "/".parse().unwrap(),
+                    headers,
+                    extensions,
+                    credentials: Some(s3s::auth::Credentials {
+                        access_key: key.to_owned(),
+                        secret_key: s3s::auth::SecretKey::from("test-user-secret".to_owned()),
+                    }),
+                    region: None,
+                    service: None,
+                    trailing_headers: None,
+                }
+            };
+            for (client, allowed) in [(Some("203.0.113.17"), false), (Some("10.8.7.6"), true), (None, true)] {
+                let req = request("proxy-admin", client);
+                assert_eq!(policy_source_addr(&req.extensions).unwrap().port(), 4567);
+                let result = authorize_admin_request(&req, vec![admin_action()]).await;
+                if allowed {
+                    result.expect("verified private client is allowed");
+                } else {
+                    assert_eq!(result.unwrap_err().code(), &s3s::S3ErrorCode::AccessDenied);
+                }
+                let mut req = request("proxy-admin", client);
+                req.method = http::Method::POST;
+                req.input = Body::from("Action=AssumeRole&Version=invalid-version".to_owned());
+                let error = crate::admin::handlers::sts::AssumeRoleHandle {}
+                    .call(req, matchit::Params::new())
+                    .await
+                    .unwrap_err();
+                if allowed {
+                    assert_eq!(error.code(), &s3s::S3ErrorCode::InvalidArgument);
+                    assert_eq!(
+                        error.message(),
+                        Some("not support version"),
+                        "only an authorized caller reaches version validation"
+                    );
+                } else {
+                    assert_eq!(error.code(), &s3s::S3ErrorCode::AccessDenied);
+                }
+                let response = crate::admin::handlers::is_admin::IsAdminHandler {}
+                    .call(request("proxy-admin", client), matchit::Params::new())
+                    .await
+                    .unwrap();
+                let mut body = response.output.1;
+                let json: serde_json::Value = serde_json::from_slice(&body.store_all_limited(4096).await.unwrap()).unwrap();
+                assert_eq!(json["is_admin"], allowed);
+            }
+            let mut routes = matchit::Router::new();
+            routes.insert("/usage/{bucket}", ()).unwrap();
+            for (bucket, allowed) in [("usage-allowed", true), ("usage-secret", false)] {
+                let path = format!("/usage/{bucket}");
+                let matched = routes.at(&path).unwrap();
+                let mut req = request("scoped-usage", None);
+                req.uri = format!("{path}?unexpected=1").parse().unwrap();
+                let error = crate::admin::handlers::usage_prefix::BucketPrefixUsageHandler {}
+                    .call(req, matched.params)
+                    .await
+                    .unwrap_err();
+                if allowed {
+                    assert_eq!(error.code(), &s3s::S3ErrorCode::InvalidArgument);
+                    assert_eq!(error.message(), Some("unknown query parameter: unexpected"));
+                } else {
+                    assert_eq!(error.code(), &s3s::S3ErrorCode::AccessDenied);
+                }
+            }
+            if let Some(previous) = previous {
+                publish_test_app_context(previous);
+            }
+        });
+    }
+
     /// Owner (root/admin) credential is authorized for an admin action.
     #[tokio::test]
     async fn admin_owner_credential_is_allowed() {
diff --git a/rustfs/src/admin/handlers/account.rs b/rustfs/src/admin/handlers/account.rs
index 464a4e8ba..8fa4cb8d4 100644
--- a/rustfs/src/admin/handlers/account.rs
+++ b/rustfs/src/admin/handlers/account.rs
@@ -42,7 +42,6 @@ use crate::admin::service::caller_identity::{CallerIdentity, oidc_profile_fields
 use crate::admin::storage_api::s3::{self, Body, S3ErrorCode, S3Request, S3Response, S3Result};
 use crate::admin::utils::read_compatible_admin_body;
 use crate::auth::constant_time_eq;
-use crate::server::RemoteAddr;
 use http::StatusCode;
 use hyper::Method;
 use matchit::Params;
@@ -162,6 +161,13 @@ pub struct ChangeOwnPasswordHandler {}
 #[async_trait::async_trait]
 impl Operation for ChangeOwnPasswordHandler {
     async fn call(&self, req: S3Request<Body>, _params: Params<'_, '_>) -> S3Result<S3Response<(StatusCode, Body)>> {
+        let signing_secret = req
+            .credentials
+            .as_ref()
+            .ok_or_else(|| s3::error(S3ErrorCode::AccessDenied, "authentication required"))?
+            .secret_key
+            .expose()
+            .to_string();
         let caller = CallerIdentity::resolve(&req).await?;
         let audit = AccountAuditContext::from_request(&req);
 
@@ -203,7 +209,9 @@ impl Operation for ChangeOwnPasswordHandler {
             return Err(s3::error(S3ErrorCode::InvalidRequest, "the calling identity no longer exists"));
         };
 
-        if !constant_time_eq(&request.current_secret_key, &stored.credentials.secret_key) {
+        if !constant_time_eq(&request.current_secret_key, &stored.credentials.secret_key)
+            || !constant_time_eq(&request.current_secret_key, &signing_secret)
+        {
             warn!(
                 component = LOG_COMPONENT_ADMIN,
                 subsystem = LOG_SUBSYSTEM_ACCOUNT,
@@ -256,31 +264,16 @@ impl Operation for ChangeOwnPasswordHandler {
             let iam_store =
                 current_ready_iam_handle().map_err(|_| s3::error(S3ErrorCode::InternalError, "iam is not initialized"))?;
 
-            let (updated_at, status) = iam_store
-                .set_user_secret_key(&access_key, &new_secret_key)
+            let (updated_at, status, revoked) = iam_store
+                .change_own_secret_key(&access_key, &signing_secret, &new_secret_key)
                 .await
-                .map_err(iam_error_to_s3_error)?;
-
-            // Sessions minted under the old secret must not outlive it. A
-            // failure here is reported but does not undo the rotation: the new
-            // secret is already authoritative, and re-running the revocation is
-            // safe, whereas rolling the secret back would resurrect it.
-            let revoked = match iam_store.revoke_sts_sessions_for_parent(&access_key).await {
-                Ok(revoked) => revoked,
-                Err(err) => {
-                    warn!(
-                        component = LOG_COMPONENT_ADMIN,
-                        subsystem = LOG_SUBSYSTEM_ACCOUNT,
-                        event = EVENT_ADMIN_ACCOUNT_STATE,
-                        action = "change_own_password",
-                        access_key = %MaskedAccessKey(&access_key),
-                        result = "session_revocation_incomplete",
-                        error = ?err,
-                        "admin account state"
-                    );
-                    0
-                }
-            };
+                .map_err(|error| {
+                    if matches!(error, rustfs_iam::error::Error::IAMActionNotAllowed) {
+                        s3::error(S3ErrorCode::InvalidRequest, "the current secret key is incorrect")
+                    } else {
+                        iam_error_to_s3_error(error)
+                    }
+                })?;
 
             emit_audit(
                 &audit_for_task,
@@ -378,7 +371,7 @@ impl Operation for SetUserSecretKeyHandler {
             caller.is_owner,
             false,
             vec![Action::AdminAction(AdminAction::CreateUserAdminAction)],
-            req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+            crate::admin::auth::policy_source_addr(&req.extensions),
         )
         .await
         .inspect_err(|_| {
@@ -424,28 +417,11 @@ impl Operation for SetUserSecretKeyHandler {
                 ));
             }
 
-            let (updated_at, status) = iam_store
-                .set_user_secret_key(&target, &request.secret_key)
+            let (updated_at, status, revoked) = iam_store
+                .rotate_user_secret_key(&target, &request.secret_key)
                 .await
                 .map_err(iam_error_to_s3_error)?;
 
-            let revoked = match iam_store.revoke_sts_sessions_for_parent(&target).await {
-                Ok(revoked) => revoked,
-                Err(err) => {
-                    warn!(
-                        component = LOG_COMPONENT_ADMIN,
-                        subsystem = LOG_SUBSYSTEM_ACCOUNT,
-                        event = EVENT_ADMIN_ACCOUNT_STATE,
-                        action = "set_user_secret_key",
-                        access_key = %MaskedAccessKey(&target),
-                        result = "session_revocation_incomplete",
-                        error = ?err,
-                        "admin account state"
-                    );
-                    0
-                }
-            };
-
             emit_audit(
                 &audit_for_task,
                 AccountAuditRecord::success(AccountAuditOperation::ResetUserPassword, &target, identity_type)
@@ -648,16 +624,23 @@ mod tests {
     #[test]
     fn both_rotation_handlers_broadcast_after_revoking_sessions() {
         let src = include_str!("account.rs");
-        for marker in [
-            "impl Operation for ChangeOwnPasswordHandler",
-            "impl Operation for SetUserSecretKeyHandler",
+        // Session revocation now runs inside the IAM rotation call, under the
+        // per-key mutation lock, so the handler must reach that call before it
+        // broadcasts the new secret to peer sites.
+        for (marker, rotation) in [
+            ("impl Operation for ChangeOwnPasswordHandler", "change_own_secret_key("),
+            ("impl Operation for SetUserSecretKeyHandler", "rotate_user_secret_key("),
         ] {
             let start = src.find(marker).expect("handler should exist");
             let block = &src[start..];
             let block = &block[..block.find("\n}\n").expect("handler block end")];
             let revoke = block
-                .find("revoke_sts_sessions_for_parent")
-                .expect("handler must revoke sessions");
+                .find(rotation)
+                .expect("handler must rotate through the IAM call that revokes sessions");
+            assert!(
+                !block.contains("revoke_sts_sessions_for_parent"),
+                "{marker}: revocation belongs to the locked IAM rotation, not a separate handler step"
+            );
             let broadcast = block
                 .find("broadcast_secret_key_rotation(")
                 .expect("handler must broadcast the rotation to peer sites");
diff --git a/rustfs/src/admin/handlers/account_info.rs b/rustfs/src/admin/handlers/account_info.rs
index 72f16335f..3aae7f6d2 100644
--- a/rustfs/src/admin/handlers/account_info.rs
+++ b/rustfs/src/admin/handlers/account_info.rs
@@ -22,7 +22,7 @@ use crate::admin::storage_api::contract::bucket::{BucketOperations, BucketOption
 use crate::admin::storage_api::data_usage::{apply_bucket_usage_memory_overlay, load_admin_data_usage_from_backend_cached};
 use crate::admin::storage_api::metadata_sys;
 use crate::auth::get_condition_values;
-use crate::server::{ADMIN_PREFIX, RemoteAddr};
+use crate::server::ADMIN_PREFIX;
 use http::{HeaderMap, HeaderValue};
 use hyper::{Method, StatusCode};
 use matchit::Params;
@@ -146,7 +146,7 @@ impl Operation for AccountInfoHandler {
         let claims = cred.claims.as_ref().unwrap_or(&default_claims);
 
         let cred_clone = cred.clone();
-        let remote_addr = req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0));
+        let remote_addr = crate::admin::auth::policy_source_addr(&req.extensions);
         let conditions = get_condition_values(&req.headers, &cred_clone, None, None, remote_addr);
         let cred_clone = Arc::new(cred_clone);
         let conditions = Arc::new(conditions);
diff --git a/rustfs/src/admin/handlers/durability.rs b/rustfs/src/admin/handlers/durability.rs
index cba9351a1..63da16c85 100644
--- a/rustfs/src/admin/handlers/durability.rs
+++ b/rustfs/src/admin/handlers/durability.rs
@@ -28,7 +28,6 @@ use crate::admin::storage_api::bucket::metadata::BUCKET_DURABILITY_CONFIG;
 use crate::admin::storage_api::bucket::metadata_sys;
 use crate::auth::{check_key_valid, get_session_token};
 use crate::server::ADMIN_PREFIX;
-use crate::server::RemoteAddr;
 use hyper::{Method, StatusCode};
 use matchit::Params;
 use rustfs_policy::policy::action::{Action, AdminAction};
@@ -127,7 +126,7 @@ async fn authenticate_admin(req: &S3Request<Body>) -> S3Result<()> {
 
     let (cred, owner) = check_key_valid(get_session_token(&req.uri, &req.headers).unwrap_or_default(), &cred.access_key).await?;
 
-    let remote_addr = req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0));
+    let remote_addr = crate::admin::auth::policy_source_addr(&req.extensions);
     validate_admin_request(
         &req.headers,
         &cred,
diff --git a/rustfs/src/admin/handlers/group.rs b/rustfs/src/admin/handlers/group.rs
index 5c8d220b9..bcac54715 100644
--- a/rustfs/src/admin/handlers/group.rs
+++ b/rustfs/src/admin/handlers/group.rs
@@ -434,7 +434,7 @@ impl Operation for SetGroupStatus {
 pub struct UpdateGroupMembers {}
 #[async_trait::async_trait]
 impl Operation for UpdateGroupMembers {
-    async fn call(&self, req: S3Request<Body>, _params: Params<'_, '_>) -> S3Result<S3Response<(StatusCode, Body)>> {
+    async fn call(&self, mut req: S3Request<Body>, _params: Params<'_, '_>) -> S3Result<S3Response<(StatusCode, Body)>> {
         warn!(
             event = EVENT_ADMIN_GROUP_STATE,
             component = LOG_COMPONENT_ADMIN,
@@ -448,9 +448,16 @@ impl Operation for UpdateGroupMembers {
             return Err(s3_error!(InvalidRequest, "authentication required"));
         }
 
-        authorize_admin_request(&req, vec![Action::AdminAction(AdminAction::AddUserToGroupAdminAction)]).await?;
+        authorize_admin_request(
+            &req,
+            vec![
+                Action::AdminAction(AdminAction::AddUserToGroupAdminAction),
+                Action::AdminAction(AdminAction::RemoveUserFromGroupAdminAction),
+            ],
+        )
+        .await?;
 
-        let mut input = req.input;
+        let mut input = std::mem::take(&mut req.input);
         let body = match input.store_all_limited(MAX_ADMIN_REQUEST_BODY_SIZE).await {
             Ok(b) => b,
             Err(e) => {
@@ -470,6 +477,13 @@ impl Operation for UpdateGroupMembers {
         let args: GroupAddRemove = serde_json::from_slice(&body)
             .map_err(|e| S3Error::with_message(S3ErrorCode::InvalidRequest, format!("invalid JSON: {e}")))?;
 
+        let action = if args.is_remove {
+            AdminAction::RemoveUserFromGroupAdminAction
+        } else {
+            AdminAction::AddUserToGroupAdminAction
+        };
+        authorize_admin_request(&req, vec![Action::AdminAction(action)]).await?;
+
         warn!(
             event = EVENT_ADMIN_GROUP_STATE,
             component = LOG_COMPONENT_ADMIN,
@@ -719,6 +733,143 @@ mod tests {
         &block[..end]
     }
 
+    #[tokio::test]
+    #[serial_test::serial]
+    async fn group_members_handler_enforces_add_and_remove_permissions() {
+        use crate::admin::runtime_sources::{AppContext, IamInterface, KmsInterface, publish_test_app_context};
+        use rustfs_iam::store::{Store as _, UserType, object::ObjectStore};
+        use rustfs_madmin::{AccountStatus, AddOrUpdateUserReq};
+        use rustfs_policy::policy::Policy;
+        use std::sync::Arc;
+
+        struct ReadyIam(Arc<rustfs_iam::sys::IamSys<ObjectStore>>);
+        impl IamInterface for ReadyIam {
+            fn handle(&self) -> Arc<rustfs_iam::sys::IamSys<ObjectStore>> {
+                Arc::clone(&self.0)
+            }
+            fn is_ready(&self) -> bool {
+                true
+            }
+        }
+        struct TestKms;
+        impl KmsInterface for TestKms {
+            fn handle(&self) -> Arc<rustfs_kms::KmsServiceManager> {
+                Arc::new(rustfs_kms::KmsServiceManager::new())
+            }
+        }
+
+        let (_directory, _paths, store) = crate::app::gating_test_env::isolated_multi_pool_ecstore().await;
+        ObjectStore::new(store.clone())
+            .save_iam_config(
+                serde_json::json!({"version": 1}),
+                format!("{}/format.json", *rustfs_iam::store::object::IAM_CONFIG_PREFIX),
+            )
+            .await
+            .expect("seed IAM format");
+        let iam = rustfs_iam::build_iam_sys(store.clone()).await.expect("initialize IAM");
+        for key in ["group-adder", "group-remover", "group-member"] {
+            iam.create_user(
+                key,
+                &AddOrUpdateUserReq {
+                    secret_key: "group-user-secret".to_owned(),
+                    policy: None,
+                    status: AccountStatus::Enabled,
+                },
+            )
+            .await
+            .expect("create group test user");
+        }
+        for (key, allow, deny) in [
+            ("group-adder", "admin:AddUserToGroup", "admin:RemoveUserFromGroup"),
+            ("group-remover", "admin:RemoveUserFromGroup", "admin:AddUserToGroup"),
+        ] {
+            let document = serde_json::json!({"Version": "2012-10-17", "Statement": [
+                {"Effect": "Allow", "Action": [allow]}, {"Effect": "Deny", "Action": [deny]}
+            ]});
+            iam.set_policy(
+                key,
+                Policy::parse_config(&serde_json::to_vec(&document).expect("policy JSON")).expect("parse policy"),
+            )
+            .await
+            .expect("store delegated policy");
+            iam.policy_db_set(key, UserType::Reg, false, key)
+                .await
+                .expect("attach delegated policy");
+        }
+        iam.add_users_to_group("guardrail", vec!["group-member".to_owned()])
+            .await
+            .expect("seed protected group");
+        let context = Arc::new(AppContext::new(store, Arc::new(ReadyIam(Arc::clone(&iam))), Arc::new(TestKms)));
+        assert!(context.publish_action_credentials(rustfs_credentials::Credentials {
+            access_key: "group-test-root".to_owned(),
+            secret_key: "group-root-secret".to_owned(),
+            status: "on".to_owned(),
+            ..Default::default()
+        }));
+        publish_test_app_context(context);
+
+        for (key, remove, allowed) in [
+            ("group-adder", true, false),
+            ("group-remover", false, false),
+            ("group-remover", true, true),
+            ("group-adder", false, true),
+        ] {
+            let before = iam
+                .get_group_description("guardrail")
+                .await
+                .expect("read original membership")
+                .members;
+            let mut req = credential_less_request(Method::PUT, "/rustfs/admin/v3/update-group-members");
+            req.credentials = Some(s3s::auth::Credentials {
+                access_key: key.to_owned(),
+                secret_key: s3s::auth::SecretKey::from("group-user-secret".to_owned()),
+            });
+            req.input = Body::from(
+                serde_json::to_vec(&serde_json::json!({
+                    "group": "guardrail", "members": ["group-member"], "groupStatus": "enabled", "isRemove": remove
+                }))
+                .expect("group update JSON"),
+            );
+            let result = UpdateGroupMembers {}.call(req, Params::new()).await;
+            let after = iam
+                .get_group_description("guardrail")
+                .await
+                .expect("read resulting membership")
+                .members;
+            if allowed {
+                result.expect("matching delegated action permits the mutation");
+                assert_eq!(after.contains(&"group-member".to_owned()), !remove);
+            } else {
+                let error = result.expect_err("the opposite action must not authorize the mutation");
+                assert_eq!(error.code(), &S3ErrorCode::AccessDenied);
+                assert_eq!(after, before, "a rejected mutation must preserve the group");
+            }
+        }
+    }
+
+    #[test]
+    fn update_group_members_authorizes_the_decoded_mutation() {
+        let source = include_str!("group.rs")
+            .split("\n#[cfg(test)]\n")
+            .next()
+            .expect("production source");
+        let handler = source_block(source, "impl Operation for UpdateGroupMembers");
+        assert_eq!(handler.matches("authorize_admin_request(").count(), 2);
+        let decoded = handler
+            .find("let args: GroupAddRemove")
+            .expect("decode request before choosing action");
+        let action = handler
+            .find("let action = if args.is_remove")
+            .expect("body controls requested action");
+        let gate = handler.rfind("authorize_admin_request(").expect("mutation authorization");
+        assert!(decoded < action && action < gate);
+        assert!(handler[action..gate].contains("AdminAction::RemoveUserFromGroupAdminAction"));
+        assert!(handler[action..gate].contains("AdminAction::AddUserToGroupAdminAction"));
+        for mutation in [".remove_users_from_group(", ".add_users_to_group("] {
+            assert!(gate < handler.find(mutation).expect("group mutation"));
+        }
+    }
+
     #[test]
     fn group_handlers_use_the_shared_admin_gate_with_their_actions() {
         let production = include_str!("group.rs")
@@ -731,7 +882,6 @@ mod tests {
             ("GetGroup", "GetGroupAdminAction"),
             ("DeleteGroup", "RemoveUserFromGroupAdminAction"),
             ("SetGroupStatus", "EnableGroupAdminAction"),
-            ("UpdateGroupMembers", "AddUserToGroupAdminAction"),
         ] {
             let block = source_block(production, &format!("impl Operation for {handler}"));
             assert_eq!(
diff --git a/rustfs/src/admin/handlers/heal.rs b/rustfs/src/admin/handlers/heal.rs
index d1cdfdbe3..af95c2e79 100644
--- a/rustfs/src/admin/handlers/heal.rs
+++ b/rustfs/src/admin/handlers/heal.rs
@@ -1474,7 +1474,7 @@ async fn authenticate_heal_admin_request(req: &S3Request<Body>) -> S3Result<Stri
         owner,
         false,
         vec![Action::AdminAction(AdminAction::HealAdminAction)],
-        req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+        crate::admin::auth::policy_source_addr(&req.extensions),
     )
     .await?;
     Ok(cred.access_key)
diff --git a/rustfs/src/admin/handlers/idp_compat.rs b/rustfs/src/admin/handlers/idp_compat.rs
index bc6417bc1..9e6224942 100644
--- a/rustfs/src/admin/handlers/idp_compat.rs
+++ b/rustfs/src/admin/handlers/idp_compat.rs
@@ -48,7 +48,7 @@ use crate::admin::router::{AdminOperation, Operation, S3Router};
 use crate::admin::runtime_sources::{current_app_context, current_ready_iam_handle, current_server_config_for_context};
 use crate::admin::utils::is_compat_admin_request;
 use crate::auth::{check_key_valid, get_session_token};
-use crate::server::{ADMIN_PREFIX, RemoteAddr};
+use crate::server::ADMIN_PREFIX;
 use http::StatusCode;
 use hyper::Method;
 use matchit::Params;
@@ -981,7 +981,7 @@ async fn authorize_action(req: &S3Request<Body>, cred: &StoredCredentials, owner
         owner,
         false,
         vec![Action::AdminAction(action)],
-        req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+        crate::admin::auth::policy_source_addr(&req.extensions),
     )
     .await
 }
diff --git a/rustfs/src/admin/handlers/is_admin.rs b/rustfs/src/admin/handlers/is_admin.rs
index 7e29c4bff..e43d65c89 100644
--- a/rustfs/src/admin/handlers/is_admin.rs
+++ b/rustfs/src/admin/handlers/is_admin.rs
@@ -66,7 +66,8 @@ impl Operation for IsAdminHandler {
             let empty_claims = HashMap::new();
             let iam_store = crate::admin::runtime_sources::current_ready_iam_handle()
                 .map_err(|_| s3_error!(InternalError, "iam not init"))?;
-            let conditions = get_condition_values(&req.headers, &cred, None, None, None);
+            let conditions =
+                get_condition_values(&req.headers, &cred, None, None, crate::admin::auth::policy_source_addr(&req.extensions));
             iam_store
                 .is_allowed(&Args {
                     account: &cred.access_key,
diff --git a/rustfs/src/admin/handlers/kms_backup.rs b/rustfs/src/admin/handlers/kms_backup.rs
index ba047b77d..29d4cdec4 100644
--- a/rustfs/src/admin/handlers/kms_backup.rs
+++ b/rustfs/src/admin/handlers/kms_backup.rs
@@ -46,7 +46,7 @@ use crate::admin::router::{AdminOperation, Operation, S3Router};
 use crate::admin::runtime_sources::{current_deployment_id, current_kms_runtime_service_manager};
 use crate::admin::utils::json_response;
 use crate::auth::{check_key_valid, get_session_token};
-use crate::server::{ADMIN_PREFIX, RemoteAddr};
+use crate::server::ADMIN_PREFIX;
 use base64_simd::STANDARD as BASE64;
 use hyper::{Method, StatusCode};
 use matchit::Params;
@@ -923,7 +923,7 @@ async fn authorize(
             owner,
             false,
             actions,
-            req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+            crate::admin::auth::policy_source_addr(&req.extensions),
         )
         .await,
         operation,
diff --git a/rustfs/src/admin/handlers/kms_dynamic.rs b/rustfs/src/admin/handlers/kms_dynamic.rs
index 2705fe1fd..0afcd2b45 100644
--- a/rustfs/src/admin/handlers/kms_dynamic.rs
+++ b/rustfs/src/admin/handlers/kms_dynamic.rs
@@ -28,7 +28,7 @@ use crate::admin::storage_api::error::StorageError;
 use crate::admin::storage_api::runtime::ECStore;
 use crate::admin::storage_api::s3::{S3ErrorCode, error as admin_s3_error};
 use crate::auth::{check_key_valid, get_session_token};
-use crate::server::{ADMIN_PREFIX, RemoteAddr};
+use crate::server::ADMIN_PREFIX;
 use hyper::{Method, StatusCode};
 use matchit::Params;
 use rustfs_config::MAX_ADMIN_REQUEST_BODY_SIZE;
@@ -859,7 +859,7 @@ impl Operation for ConfigureKmsHandler {
                 owner,
                 false,
                 kms_configure_actions(),
-                req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                crate::admin::auth::policy_source_addr(&req.extensions),
             )
             .await,
             KmsAdminOperation::Configure,
@@ -1012,7 +1012,7 @@ impl Operation for StartKmsHandler {
                 owner,
                 false,
                 kms_service_control_actions(),
-                req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                crate::admin::auth::policy_source_addr(&req.extensions),
             )
             .await,
             KmsAdminOperation::Start,
@@ -1169,7 +1169,7 @@ impl Operation for StopKmsHandler {
                 owner,
                 false,
                 kms_service_control_actions(),
-                req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                crate::admin::auth::policy_source_addr(&req.extensions),
             )
             .await,
             KmsAdminOperation::Stop,
@@ -1271,7 +1271,7 @@ impl Operation for ReloadKmsHandler {
                 owner,
                 false,
                 kms_service_control_actions(),
-                req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                crate::admin::auth::policy_source_addr(&req.extensions),
             )
             .await,
             KmsAdminOperation::Reload,
@@ -1365,7 +1365,7 @@ impl Operation for GetKmsStatusHandler {
             owner,
             false,
             kms_service_control_actions(),
-            req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+            crate::admin::auth::policy_source_addr(&req.extensions),
         )
         .await?;
 
@@ -1459,7 +1459,7 @@ impl Operation for ReconfigureKmsHandler {
                 owner,
                 false,
                 kms_configure_actions(),
-                req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                crate::admin::auth::policy_source_addr(&req.extensions),
             )
             .await,
             KmsAdminOperation::Reconfigure,
diff --git a/rustfs/src/admin/handlers/kms_key_lifecycle.rs b/rustfs/src/admin/handlers/kms_key_lifecycle.rs
index 93ad7834e..39643ec91 100644
--- a/rustfs/src/admin/handlers/kms_key_lifecycle.rs
+++ b/rustfs/src/admin/handlers/kms_key_lifecycle.rs
@@ -21,7 +21,7 @@ use crate::admin::router::{AdminOperation, Operation, S3Router};
 use crate::admin::runtime_sources::current_kms_runtime_service_manager;
 use crate::admin::utils::{extract_query_params, json_response};
 use crate::auth::{check_key_valid, get_session_token};
-use crate::server::{ADMIN_PREFIX, RemoteAddr};
+use crate::server::ADMIN_PREFIX;
 use hyper::{Method, StatusCode};
 use matchit::Params;
 use rustfs_config::MAX_ADMIN_REQUEST_BODY_SIZE;
@@ -270,7 +270,7 @@ async fn handle_lifecycle_request(
             owner,
             false,
             actions,
-            req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+            crate::admin::auth::policy_source_addr(&req.extensions),
             scoped.as_deref().unwrap_or_default(),
         )
         .await,
diff --git a/rustfs/src/admin/handlers/kms_key_metadata.rs b/rustfs/src/admin/handlers/kms_key_metadata.rs
index 7db8ed396..e47bdac1a 100644
--- a/rustfs/src/admin/handlers/kms_key_metadata.rs
+++ b/rustfs/src/admin/handlers/kms_key_metadata.rs
@@ -25,7 +25,7 @@ use crate::admin::router::{AdminOperation, Operation, S3Router};
 use crate::admin::runtime_sources::current_kms_runtime_service_manager;
 use crate::admin::utils::json_response;
 use crate::auth::{check_key_valid, get_session_token};
-use crate::server::{ADMIN_PREFIX, RemoteAddr};
+use crate::server::ADMIN_PREFIX;
 use hyper::{Method, StatusCode};
 use matchit::Params;
 use rustfs_config::MAX_ADMIN_REQUEST_BODY_SIZE;
@@ -327,7 +327,7 @@ async fn handle_metadata_request(
             owner,
             false,
             actions,
-            req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+            crate::admin::auth::policy_source_addr(&req.extensions),
             scoped.as_deref().unwrap_or_default(),
         )
         .await,
diff --git a/rustfs/src/admin/handlers/kms_keys.rs b/rustfs/src/admin/handlers/kms_keys.rs
index be6e0b8c1..d7460d9c9 100644
--- a/rustfs/src/admin/handlers/kms_keys.rs
+++ b/rustfs/src/admin/handlers/kms_keys.rs
@@ -22,7 +22,7 @@ use crate::admin::storage_api::s3;
 use crate::admin::utils::extract_query_params;
 use crate::auth::{check_key_valid, get_session_token};
 use crate::kms_deletion_gate::current_key_impact;
-use crate::server::{ADMIN_PREFIX, RemoteAddr};
+use crate::server::ADMIN_PREFIX;
 use hyper::{HeaderMap, Method, StatusCode};
 use matchit::Params;
 use rustfs_config::MAX_ADMIN_REQUEST_BODY_SIZE;
@@ -325,7 +325,7 @@ impl Operation for CreateKeyHandler {
                 owner,
                 false,
                 kms_create_key_actions(),
-                req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                crate::admin::auth::policy_source_addr(&req.extensions),
             )
             .await,
             KmsAuditOperation::CreateKey,
@@ -418,7 +418,7 @@ impl Operation for DescribeKeyHandler {
                 owner,
                 false,
                 kms_describe_key_actions(),
-                req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                crate::admin::auth::policy_source_addr(&req.extensions),
                 requested_key_id.as_deref().unwrap_or_default(),
             )
             .await,
@@ -1488,7 +1488,7 @@ impl Operation for ListKeysHandler {
                 owner,
                 false,
                 kms_list_keys_actions(),
-                req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                crate::admin::auth::policy_source_addr(&req.extensions),
             )
             .await,
             KmsAuditOperation::ListKeys,
@@ -1583,7 +1583,7 @@ impl Operation for GenerateDataKeyHandler {
                 owner,
                 false,
                 kms_generate_data_key_actions(),
-                req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                crate::admin::auth::policy_source_addr(&req.extensions),
                 parsed.as_ref().map(|request| request.key_id.as_str()).unwrap_or_default(),
             )
             .await,
@@ -1664,7 +1664,7 @@ impl Operation for CreateKmsKeyHandler {
                 owner,
                 false,
                 kms_create_key_actions(),
-                req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                crate::admin::auth::policy_source_addr(&req.extensions),
             )
             .await,
             KmsAuditOperation::CreateKey,
@@ -1943,7 +1943,7 @@ impl Operation for DeleteKmsKeyHandler {
                 owner,
                 false,
                 kms_delete_key_actions(),
-                req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                crate::admin::auth::policy_source_addr(&req.extensions),
                 scoped.as_deref().unwrap_or_default(),
             )
             .await,
@@ -2111,7 +2111,7 @@ impl Operation for CancelKmsKeyDeletionHandler {
                 owner,
                 false,
                 kms_delete_key_actions(),
-                req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                crate::admin::auth::policy_source_addr(&req.extensions),
                 scoped.as_deref().unwrap_or_default(),
             )
             .await,
@@ -2263,7 +2263,7 @@ impl Operation for ListKmsKeysHandler {
                 owner,
                 false,
                 kms_list_keys_actions(),
-                req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                crate::admin::auth::policy_source_addr(&req.extensions),
             )
             .await,
             KmsAuditOperation::ListKeys,
@@ -2459,7 +2459,7 @@ impl Operation for DescribeKmsKeyHandler {
                 owner,
                 false,
                 kms_describe_key_actions(),
-                req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                crate::admin::auth::policy_source_addr(&req.extensions),
                 params.get("key_id").unwrap_or_default(),
             )
             .await,
diff --git a/rustfs/src/admin/handlers/mfa.rs b/rustfs/src/admin/handlers/mfa.rs
index 90ebd7ef5..741728f44 100644
--- a/rustfs/src/admin/handlers/mfa.rs
+++ b/rustfs/src/admin/handlers/mfa.rs
@@ -51,7 +51,6 @@ use crate::admin::storage_api::runtime::ECStore;
 use crate::admin::storage_api::s3::{self, Body, S3Error, S3ErrorCode, S3Request, S3Response, S3Result};
 use crate::admin::utils::read_compatible_admin_body;
 use crate::auth::constant_time_eq;
-use crate::server::RemoteAddr;
 use http::StatusCode;
 use hyper::Method;
 use matchit::Params;
@@ -484,7 +483,7 @@ impl Operation for UserMfaStatusHandler {
             caller.is_owner,
             false,
             vec![Action::AdminAction(AdminAction::GetUserAdminAction)],
-            req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+            crate::admin::auth::policy_source_addr(&req.extensions),
         )
         .await?;
 
@@ -521,7 +520,7 @@ impl Operation for UserMfaResetHandler {
             caller.is_owner,
             false,
             vec![Action::AdminAction(AdminAction::EnableUserAdminAction)],
-            req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+            crate::admin::auth::policy_source_addr(&req.extensions),
         )
         .await
         .inspect_err(|_| {
diff --git a/rustfs/src/admin/handlers/plugin_delegation.rs b/rustfs/src/admin/handlers/plugin_delegation.rs
index 57419ba18..ca2d867b5 100644
--- a/rustfs/src/admin/handlers/plugin_delegation.rs
+++ b/rustfs/src/admin/handlers/plugin_delegation.rs
@@ -11,7 +11,7 @@ use crate::admin::{
 };
 use crate::{
     auth::{check_key_valid_with_context, get_session_token},
-    server::{ADMIN_PREFIX, RemoteAddr},
+    server::ADMIN_PREFIX,
 };
 use http::{HeaderMap, HeaderValue, Method, StatusCode};
 use matchit::Params;
@@ -97,7 +97,7 @@ pub(super) async fn owner(
         &credentials,
         false,
         Action::AdminAction(action),
-        req.extensions.get::<Option<RemoteAddr>>().and_then(|a| a.map(|a| a.0)),
+        crate::admin::auth::policy_source_addr(&req.extensions),
         AdminResourceScope::bucket_object("", ""),
     )
     .await?;
diff --git a/rustfs/src/admin/handlers/quota.rs b/rustfs/src/admin/handlers/quota.rs
index 43a18a6e7..4b02ebdbc 100644
--- a/rustfs/src/admin/handlers/quota.rs
+++ b/rustfs/src/admin/handlers/quota.rs
@@ -30,7 +30,6 @@ use crate::admin::storage_api::contract::bucket::{BucketOperations as _, BucketO
 use crate::auth::{check_key_valid, get_session_token};
 use crate::error::ApiError;
 use crate::server::ADMIN_PREFIX;
-use crate::server::RemoteAddr;
 use hyper::{Method, StatusCode};
 use matchit::Params;
 use rustfs_madmin::{SITE_REPL_API_VERSION, SRBucketMeta};
@@ -397,7 +396,7 @@ impl Operation for SetBucketQuotaHandler {
         let (cred, owner) =
             check_key_valid(get_session_token(&req.uri, &req.headers).unwrap_or_default(), &cred.access_key).await?;
 
-        let remote_addr = req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0));
+        let remote_addr = crate::admin::auth::policy_source_addr(&req.extensions);
         validate_admin_request(
             &req.headers,
             &cred,
@@ -538,7 +537,7 @@ impl Operation for GetBucketQuotaHandler {
         if bucket.is_empty() {
             return Err(s3_error!(InvalidRequest, "bucket name is required"));
         }
-        let remote_addr = req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0));
+        let remote_addr = crate::admin::auth::policy_source_addr(&req.extensions);
         validate_admin_request_with_bucket(
             &req.headers,
             &cred,
@@ -607,7 +606,7 @@ impl Operation for ClearBucketQuotaHandler {
         let (cred, owner) =
             check_key_valid(get_session_token(&req.uri, &req.headers).unwrap_or_default(), &cred.access_key).await?;
 
-        let remote_addr = req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0));
+        let remote_addr = crate::admin::auth::policy_source_addr(&req.extensions);
         validate_admin_request(
             &req.headers,
             &cred,
@@ -726,7 +725,7 @@ impl Operation for GetBucketQuotaStatsHandler {
             return Err(s3_error!(InvalidRequest, "bucket name is required"));
         }
 
-        let remote_addr = req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0));
+        let remote_addr = crate::admin::auth::policy_source_addr(&req.extensions);
         validate_admin_request_with_bucket(
             &req.headers,
             &cred,
@@ -795,7 +794,7 @@ impl Operation for CheckBucketQuotaHandler {
             return Err(s3_error!(InvalidRequest, "bucket name is required"));
         }
 
-        let remote_addr = req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0));
+        let remote_addr = crate::admin::auth::policy_source_addr(&req.extensions);
         validate_admin_request_with_bucket(
             &req.headers,
             &cred,
@@ -890,7 +889,7 @@ impl Operation for MigrateBucketQuotaProtocolHandler {
         let (cred, owner) =
             check_key_valid(get_session_token(&req.uri, &req.headers).unwrap_or_default(), &cred.access_key).await?;
 
-        let remote_addr = req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0));
+        let remote_addr = crate::admin::auth::policy_source_addr(&req.extensions);
         validate_admin_request(
             &req.headers,
             &cred,
diff --git a/rustfs/src/admin/handlers/service_account.rs b/rustfs/src/admin/handlers/service_account.rs
index f046cfff7..31a1bf63c 100644
--- a/rustfs/src/admin/handlers/service_account.rs
+++ b/rustfs/src/admin/handlers/service_account.rs
@@ -18,7 +18,7 @@ use crate::admin::handlers::site_replication::{encode_service_account_replicatio
 use crate::admin::runtime_sources::current_action_credentials;
 use crate::admin::utils::{encode_compatible_admin_payload, has_space_be, is_compat_admin_request, read_compatible_admin_body};
 use crate::auth::{constant_time_eq, get_condition_values, get_session_token};
-use crate::server::{ADMIN_PREFIX, RemoteAddr};
+use crate::server::ADMIN_PREFIX;
 use crate::{
     admin::router::{AdminOperation, Operation, S3Router},
     auth::check_key_valid,
@@ -84,6 +84,25 @@ fn parse_new_service_account_policy(policy: Option<&serde_json::Value>) -> S3Res
     Ok((!policy.id.is_empty() || !policy.version.is_empty() || !policy.statements.is_empty()).then_some(policy))
 }
 
+/// Service accounts cannot delegate beyond their own lifetime. STS sessions
+/// retain the existing ability to create independently expiring service accounts.
+fn bounded_service_account_expiration(caller: &StoredCredentials, requested: Option<OffsetDateTime>) -> Option<OffsetDateTime> {
+    match caller.expiration.filter(|_| caller.is_service_account()) {
+        Some(limit) => Some(requested.map_or(limit, |expiration| expiration.min(limit))),
+        None => requested,
+    }
+}
+
+fn set_service_account_duration_condition(
+    conditions: &mut HashMap<String, Vec<String>>,
+    expiration: Option<OffsetDateTime>,
+    now: OffsetDateTime,
+) {
+    // An unlimited credential must not bypass a finite NumericGreaterThan Deny.
+    let seconds = expiration.map_or(i64::MAX, |expiration| (expiration - now).whole_seconds().max(0));
+    conditions.insert("DurationSeconds".to_string(), vec![seconds.to_string()]);
+}
+
 fn compat_time_sentinel() -> OffsetDateTime {
     OffsetDateTime::UNIX_EPOCH
 }
@@ -322,9 +341,13 @@ impl Operation for AddServiceAccount {
         let (cred, owner) =
             check_key_valid(get_session_token(&req.uri, &req.headers).unwrap_or_default(), &req_cred.access_key).await?;
 
+        if !constant_time_eq(&cred.secret_key, req_cred.secret_key.expose()) {
+            return Err(S3Error::with_message(S3ErrorCode::AccessDenied, "access denied"));
+        }
+
         let body = read_compatible_admin_body(req.input, MAX_ADMIN_REQUEST_BODY_SIZE, req.uri.path(), &cred.secret_key).await?;
 
-        let create_req: AddServiceAccountReq =
+        let mut create_req: AddServiceAccountReq =
             serde_json::from_slice(&body[..]).map_err(|e| s3_error!(InvalidRequest, "unmarshal body failed, e: {:?}", e))?;
 
         // create_req.expiration = create_req.expiration.and_then(|expire| expire.replace_millisecond(0).ok());
@@ -370,6 +393,11 @@ impl Operation for AddServiceAccount {
             return Err(s3_error!(InvalidRequest, "iam not init"));
         };
 
+        create_req.expiration = bounded_service_account_expiration(&cred, create_req.expiration);
+        let mut conditions =
+            get_condition_values(&req.headers, &cred, None, None, crate::admin::auth::policy_source_addr(&req.extensions));
+        set_service_account_duration_condition(&mut conditions, create_req.expiration, OffsetDateTime::now_utc());
+
         // This family deliberately calls `is_allowed` directly instead of going
         // through `validate_admin_request`, and must keep doing so
         // (backlog#1886). The shared helper returns as soon as *any* candidate
@@ -383,13 +411,7 @@ impl Operation for AddServiceAccount {
                 groups: &cred.groups,
                 action: Action::AdminAction(AdminAction::CreateServiceAccountAdminAction),
                 bucket: "",
-                conditions: &get_condition_values(
-                    &req.headers,
-                    &cred,
-                    None,
-                    None,
-                    req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
-                ),
+                conditions: &conditions,
                 is_owner: owner,
                 object: "",
                 claims: cred.claims_or_empty(),
@@ -444,17 +466,9 @@ impl Operation for AddServiceAccount {
         let replication_description = opts.description.clone().unwrap_or_default();
         let replication_expiration = opts.expiration;
 
-        let create_result = if is_svc_acc {
-            iam_store
-                .new_service_account_from_caller(&target_user, target_groups, opts, &cred)
-                .await
-        } else {
-            let replication_claims = opts.claims.clone().unwrap_or_default();
-            iam_store
-                .new_service_account(&target_user, target_groups, opts)
-                .await
-                .map(|(credentials, updated_at)| (credentials, updated_at, replication_claims))
-        };
+        let create_result = iam_store
+            .new_service_account_from_caller(&target_user, target_groups, opts, &cred)
+            .await;
         let (new_cred, updated_at, replication_claims) = create_result.map_err(|e| {
             debug!(
                 component = LOG_COMPONENT_ADMIN,
@@ -466,7 +480,8 @@ impl Operation for AddServiceAccount {
                 "admin service account state"
             );
             match e {
-                rustfs_iam::error::Error::InvalidAccessKeyLength
+                rustfs_iam::error::Error::InvalidArgument
+                | rustfs_iam::error::Error::InvalidAccessKeyLength
                 | rustfs_iam::error::Error::InvalidSecretKeyLength
                 | rustfs_iam::error::Error::AccessKeyAlreadyExists => iam_error_to_s3_error(e),
                 rustfs_iam::error::Error::IAMActionNotAllowed => s3_error!(AccessDenied, "access denied"),
@@ -599,6 +614,9 @@ impl Operation for UpdateServiceAccount {
             return Err(s3_error!(InvalidRequest, "get cred failed"));
         };
 
+        let (cred, owner) =
+            check_key_valid(get_session_token(&req.uri, &req.headers).unwrap_or_default(), &input_cred.access_key).await?;
+
         let Ok(iam_store) = crate::admin::runtime_sources::current_ready_iam_handle() else {
             return Err(s3_error!(InvalidRequest, "iam not init"));
         };
@@ -608,17 +626,29 @@ impl Operation for UpdateServiceAccount {
         //     s3_error!(InternalError, "get service account failed")
         // })?;
 
-        let body =
-            read_compatible_admin_body(req.input, MAX_ADMIN_REQUEST_BODY_SIZE, req.uri.path(), input_cred.secret_key.expose())
-                .await?;
+        let body = read_compatible_admin_body(req.input, MAX_ADMIN_REQUEST_BODY_SIZE, req.uri.path(), &cred.secret_key).await?;
 
-        let update_req: UpdateServiceAccountReq =
+        let mut update_req: UpdateServiceAccountReq =
             serde_json::from_slice(&body[..]).map_err(|e| s3_error!(InvalidRequest, "unmarshal body failed, e: {:?}", e))?;
 
         update_req.validate().map_err(|e| S3Error::with_message(InvalidRequest, e))?;
 
-        let (cred, owner) =
-            check_key_valid(get_session_token(&req.uri, &req.headers).unwrap_or_default(), &input_cred.access_key).await?;
+        // Keep lookup errors behind authorization even though lifetime conditions
+        // need the existing expiration when the request omits it.
+        let existing_account = iam_store.get_service_account(&access_key).await;
+
+        if update_req.new_expiration.is_some() {
+            update_req.new_expiration = bounded_service_account_expiration(&cred, update_req.new_expiration);
+        }
+        let mut conditions =
+            get_condition_values(&req.headers, &cred, None, None, crate::admin::auth::policy_source_addr(&req.extensions));
+        set_service_account_duration_condition(
+            &mut conditions,
+            update_req
+                .new_expiration
+                .or_else(|| existing_account.as_ref().ok().and_then(|(account, _)| account.expiration)),
+            OffsetDateTime::now_utc(),
+        );
 
         if !iam_store
             .is_allowed(&Args {
@@ -626,13 +656,7 @@ impl Operation for UpdateServiceAccount {
                 groups: &cred.groups,
                 action: Action::AdminAction(AdminAction::UpdateServiceAccountAdminAction),
                 bucket: "",
-                conditions: &get_condition_values(
-                    &req.headers,
-                    &cred,
-                    None,
-                    None,
-                    req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
-                ),
+                conditions: &conditions,
                 is_owner: owner,
                 object: "",
                 claims: cred.claims_or_empty(),
@@ -643,10 +667,7 @@ impl Operation for UpdateServiceAccount {
             return Err(s3_error!(AccessDenied, "access denied"));
         }
 
-        let (svc_account, _) = iam_store
-            .get_service_account(&access_key)
-            .await
-            .map_err(|e| map_service_account_lookup_error(e, "get service account failed"))?;
+        let (svc_account, _) = existing_account.map_err(|e| map_service_account_lookup_error(e, "get service account failed"))?;
 
         // The admin action permits updates within a caller's scope; only an
         // owner may cross service-account parent boundaries.
@@ -723,11 +744,6 @@ impl Operation for InfoServiceAccount {
             return Err(s3_error!(InvalidRequest, "iam not init"));
         };
 
-        let (svc_account, session_policy) = iam_store
-            .get_service_account(&access_key)
-            .await
-            .map_err(|e| map_service_account_lookup_error(e, "get service account failed"))?;
-
         let Some(input_cred) = req.credentials else {
             return Err(s3_error!(InvalidRequest, "get cred failed"));
         };
@@ -735,6 +751,11 @@ impl Operation for InfoServiceAccount {
         let (cred, owner) =
             check_key_valid(get_session_token(&req.uri, &req.headers).unwrap_or_default(), &input_cred.access_key).await?;
 
+        let (svc_account, session_policy) = iam_store
+            .get_service_account(&access_key)
+            .await
+            .map_err(|e| map_service_account_lookup_error(e, "get service account failed"))?;
+
         if !iam_store
             .is_allowed(&Args {
                 account: &cred.access_key,
@@ -746,7 +767,7 @@ impl Operation for InfoServiceAccount {
                     &cred,
                     None,
                     None,
-                    req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                    crate::admin::auth::policy_source_addr(&req.extensions),
                 ),
                 is_owner: owner,
                 object: "",
@@ -811,7 +832,7 @@ impl Operation for TemporaryAccountInfo {
                     &cred,
                     None,
                     None,
-                    req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                    crate::admin::auth::policy_source_addr(&req.extensions),
                 ),
                 is_owner: owner,
                 object: "",
@@ -872,13 +893,8 @@ impl Operation for InfoAccessKey {
 
         let target_cred = iam_store.get_user(&access_key).await.map(|identity| identity.credentials);
 
-        let conditions = get_condition_values(
-            &req.headers,
-            &cred,
-            None,
-            None,
-            req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
-        );
+        let conditions =
+            get_condition_values(&req.headers, &cred, None, None, crate::admin::auth::policy_source_addr(&req.extensions));
         let claims = cred.claims_or_empty();
 
         if !iam_store
@@ -1007,7 +1023,7 @@ impl Operation for ListServiceAccount {
                         &cred,
                         None,
                         None,
-                        req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                        crate::admin::auth::policy_source_addr(&req.extensions),
                     ),
                     is_owner: owner,
                     object: "",
@@ -1151,7 +1167,7 @@ impl Operation for ListAccessKeysBulk {
                         &cred,
                         None,
                         None,
-                        req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                        crate::admin::auth::policy_source_addr(&req.extensions),
                     ),
                     is_owner: owner,
                     object: "",
@@ -1174,7 +1190,7 @@ impl Operation for ListAccessKeysBulk {
                     &cred,
                     None,
                     None,
-                    req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                    crate::admin::auth::policy_source_addr(&req.extensions),
                 ),
                 is_owner: owner,
                 object: "",
@@ -1355,7 +1371,7 @@ impl Operation for DeleteServiceAccount {
                     &cred,
                     None,
                     None,
-                    req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+                    crate::admin::auth::policy_source_addr(&req.extensions),
                 ),
                 is_owner: owner,
                 object: "",
@@ -1444,12 +1460,168 @@ mod tests {
     use serde_json::json;
     use serde_urlencoded::from_bytes;
 
+    #[test]
+    #[serial_test::serial]
+    fn service_account_handlers_authenticate_before_decryption_or_lookup() {
+        crate::app::gating_test_env::run_large_stack_test("service-account-auth-first", || async {
+            use crate::admin::runtime_sources::IamInterface;
+            use crate::admin::runtime_sources::{AppContext, publish_test_app_context};
+            use rustfs_iam::store::object::ObjectStore;
+            use std::sync::Arc;
+            struct ReadyIam(Arc<rustfs_iam::sys::IamSys<ObjectStore>>);
+            impl IamInterface for ReadyIam {
+                fn handle(&self) -> Arc<rustfs_iam::sys::IamSys<ObjectStore>> {
+                    self.0.clone()
+                }
+                fn is_ready(&self) -> bool {
+                    true
+                }
+            }
+            let ambient = crate::app::gating_test_env::shared_gating_ambient().await;
+            let (_directory, _paths, store) = crate::app::gating_test_env::isolated_multi_pool_ecstore().await;
+            ObjectStore::new(store.clone())
+                .save_iam_config(
+                    serde_json::json!({"version": 1}),
+                    format!("{}/format.json", *rustfs_iam::store::object::IAM_CONFIG_PREFIX),
+                )
+                .await
+                .expect("initialize IAM storage");
+            let iam = rustfs_iam::build_iam_sys(store.clone()).await.expect("initialized IAM");
+            let disabled_key = format!("disabled-{}", uuid::Uuid::new_v4());
+            iam.create_user(
+                &disabled_key,
+                &rustfs_madmin::AddOrUpdateUserReq {
+                    secret_key: "disabled-user-secret".to_owned(),
+                    policy: None,
+                    status: rustfs_madmin::AccountStatus::Disabled,
+                },
+            )
+            .await
+            .expect("create disabled IAM caller");
+            let context = Arc::new(AppContext::new(store, Arc::new(ReadyIam(iam)), ambient.kms()));
+            assert!(context.publish_action_credentials(StoredCredentials {
+                access_key: "auth-first-root".to_owned(),
+                secret_key: "auth-first-root-secret".to_owned(),
+                status: "on".to_owned(),
+                ..Default::default()
+            }));
+            publish_test_app_context(context);
+            for caller in ["keystone:forged", disabled_key.as_str()] {
+                for operation in ["update-service-account", "info-service-account"] {
+                    let req = S3Request {
+                        input: Body::from(vec![0u8; 64]),
+                        method: if operation == "update-service-account" {
+                            http::Method::POST
+                        } else {
+                            http::Method::GET
+                        },
+                        uri: format!("/minio/admin/v3/{operation}?accessKey=missing-target")
+                            .parse()
+                            .unwrap(),
+                        headers: HeaderMap::new(),
+                        extensions: http::Extensions::new(),
+                        credentials: Some(s3s::auth::Credentials {
+                            access_key: caller.to_owned(),
+                            secret_key: s3s::auth::SecretKey::from("disabled-user-secret"),
+                        }),
+                        region: None,
+                        service: None,
+                        trailing_headers: None,
+                    };
+                    let result = if operation == "update-service-account" {
+                        UpdateServiceAccount {}.call(req, Params::new()).await
+                    } else {
+                        InfoServiceAccount {}.call(req, Params::new()).await
+                    };
+                    assert_eq!(
+                        result
+                            .expect_err("invalid identity precedes KDF and missing target lookup")
+                            .code(),
+                        &s3s::S3ErrorCode::InvalidAccessKeyId,
+                        "{caller}: {operation}"
+                    );
+                }
+            }
+            publish_test_app_context(ambient);
+        });
+    }
+
     #[test]
     fn access_key_query_supports_external_alias() {
         let query: AccessKeyQuery = from_bytes(b"access-key=test-access-key").expect("parse query");
         assert_eq!(query.access_key, "test-access-key");
     }
 
+    #[test]
+    fn service_account_cannot_delegate_a_longer_lifetime() {
+        let deadline = OffsetDateTime::UNIX_EPOCH + time::Duration::days(10);
+        let earlier = deadline - time::Duration::hours(1);
+        let later = deadline + time::Duration::days(365);
+        let mut caller = StoredCredentials {
+            access_key: "expiring-service".to_string(),
+            parent_user: "parent".to_string(),
+            expiration: Some(deadline),
+            claims: Some(HashMap::from([("sa-policy".to_string(), json!("inherited-policy"))])),
+            ..Default::default()
+        };
+        assert_eq!(bounded_service_account_expiration(&caller, None), Some(deadline));
+        assert_eq!(bounded_service_account_expiration(&caller, Some(later)), Some(deadline));
+        assert_eq!(bounded_service_account_expiration(&caller, Some(earlier)), Some(earlier));
+        caller.expiration = None;
+        assert_eq!(bounded_service_account_expiration(&caller, None), None);
+        caller.expiration = Some(deadline);
+        caller.claims = None;
+        caller.session_token = "signed-sts".to_string();
+        assert_eq!(
+            bounded_service_account_expiration(&caller, None),
+            None,
+            "STS retains independent service lifetime"
+        );
+        assert_eq!(bounded_service_account_expiration(&caller, Some(later)), Some(later));
+    }
+
+    #[tokio::test]
+    async fn service_account_duration_condition_enforces_finite_and_unlimited_lifetimes() {
+        let policy = Policy::parse_config(
+            br#"{"Version":"2012-10-17","Statement":[
+            {"Effect":"Allow","Action":["admin:CreateServiceAccount","admin:UpdateServiceAccount"],"Resource":"*"},
+            {"Effect":"Deny","Action":["admin:CreateServiceAccount","admin:UpdateServiceAccount"],"Resource":"*",
+             "Condition":{"NumericGreaterThan":{"svc:DurationSeconds":"3600"}}}
+        ]}"#,
+        )
+        .expect("service lifetime policy");
+        let now = OffsetDateTime::UNIX_EPOCH;
+        for (expiration, allowed) in [
+            (Some(now + time::Duration::seconds(3600)), true),
+            (Some(now + time::Duration::seconds(3601)), false),
+            (None, false),
+        ] {
+            let mut conditions = HashMap::from([("DurationSeconds".to_string(), vec!["1".to_string()])]);
+            set_service_account_duration_condition(&mut conditions, expiration, now);
+            for action in [
+                AdminAction::CreateServiceAccountAdminAction,
+                AdminAction::UpdateServiceAccountAdminAction,
+            ] {
+                assert_eq!(
+                    policy
+                        .is_allowed(&Args {
+                            account: "user",
+                            groups: &None,
+                            action: Action::AdminAction(action),
+                            conditions: &conditions,
+                            is_owner: false,
+                            claims: &HashMap::new(),
+                            deny_only: false,
+                            bucket: "",
+                            object: "",
+                        })
+                        .await,
+                    allowed
+                );
+            }
+        }
+    }
+
     #[test]
     fn non_admin_delete_is_fail_closed_on_unloadable_target() {
         // Regression (backlog#806): a non-admin caller may delete ONLY a service
diff --git a/rustfs/src/admin/handlers/sts.rs b/rustfs/src/admin/handlers/sts.rs
index 75211130c..de911332a 100644
--- a/rustfs/src/admin/handlers/sts.rs
+++ b/rustfs/src/admin/handlers/sts.rs
@@ -27,7 +27,6 @@ use crate::{
     },
     auth::{check_key_valid, get_session_token},
     server::ADMIN_PREFIX,
-    server::RemoteAddr,
 };
 use http::StatusCode;
 use http::header::HeaderValue;
@@ -54,6 +53,7 @@ use s3s::{
 use serde::Deserialize;
 use serde_json::Value;
 use serde_urlencoded::from_bytes;
+use std::collections::HashMap;
 use time::{Duration, OffsetDateTime};
 use tracing::{debug, error, warn};
 
@@ -82,6 +82,12 @@ fn clamp_assume_role_duration(duration_seconds: usize) -> usize {
     }
 }
 
+fn set_assume_role_duration_condition(conditions: &mut HashMap<String, Vec<String>>, requested: usize) -> usize {
+    let duration = clamp_assume_role_duration(requested);
+    conditions.insert("DurationSeconds".to_string(), vec![duration.to_string()]);
+    duration
+}
+
 /// Record that AssumeRole assembled its session claims without echoing any claim values.
 ///
 /// Claims carry caller-supplied identity material (parent user, session policy, arbitrary
@@ -186,7 +192,7 @@ impl Operation for AssumeRoleHandle {
 
         match body.action.as_str() {
             ASSUME_ROLE_ACTION => {
-                let remote_addr = req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0));
+                let remote_addr = crate::admin::auth::policy_source_addr(&req.extensions);
                 handle_assume_role(req.credentials, req.uri, req.headers, remote_addr, body, store, &audit).await
             }
             ASSUME_ROLE_WITH_WEB_IDENTITY_ACTION => handle_assume_role_with_web_identity(body).await,
@@ -216,6 +222,12 @@ async fn handle_assume_role(
 
     let (cred, owner) = check_key_valid(get_session_token(&uri, &headers).unwrap_or_default(), &user.access_key).await?;
 
+    // The signature was verified before the request body was consumed. A fresh
+    // IAM lookup must not silently replace the secret that authenticated it.
+    if !crate::auth::constant_time_eq(&cred.secret_key, user.secret_key.expose()) {
+        return Err(S3Error::with_message(S3ErrorCode::AccessDenied, "Access Denied"));
+    }
+
     if cred.is_temp() || cred.is_service_account() {
         return Err(s3_error!(AccessDenied, "Access Denied"));
     }
@@ -223,7 +235,8 @@ async fn handle_assume_role(
     let Ok(iam_store) = crate::admin::runtime_sources::current_ready_iam_handle() else {
         return Err(s3_error!(InvalidRequest, "iam not init"));
     };
-    let conditions = crate::auth::get_condition_values(&headers, &cred, None, None, remote_addr);
+    let mut conditions = crate::auth::get_condition_values(&headers, &cred, None, None, remote_addr);
+    let exp = set_assume_role_duration_condition(&mut conditions, body.duration_seconds);
     if !iam_store
         .is_allowed(&Args {
             account: &cred.access_key,
@@ -260,7 +273,7 @@ async fn handle_assume_role(
     // behaviour of every existing deployment is unchanged.
     let mfa_verified = enforce_second_factor(&cred.access_key, &body, store, audit).await?;
 
-    let mut claims = cred.claims.unwrap_or_default();
+    let mut claims = cred.claims.clone().unwrap_or_default();
 
     if mfa_verified {
         // Recorded on the session so a later policy condition can require it,
@@ -271,8 +284,6 @@ async fn handle_assume_role(
 
     populate_session_policy(&mut claims, &body.policy)?;
 
-    let exp = clamp_assume_role_duration(body.duration_seconds);
-
     claims.insert(
         "exp".to_string(),
         Value::Number(serde_json::Number::from(
@@ -309,9 +320,9 @@ async fn handle_assume_role(
     );
 
     let updated_at = iam_store
-        .set_temp_user(&new_cred.access_key, &new_cred, None)
+        .set_temp_user_from_parent(&new_cred, &cred)
         .await
-        .map_err(|_| s3_error!(InternalError, "set_temp_user failed"))?;
+        .map_err(super::iam_error::iam_error_to_s3_error)?;
 
     let root_access_key = current_action_credentials().map(|cred| cred.access_key);
     if root_access_key.as_deref() != Some(new_cred.parent_user.as_str())
@@ -604,6 +615,40 @@ mod tests {
         assert_eq!(clamp(999999), 43200); // clamped to max
     }
 
+    #[tokio::test]
+    async fn assume_role_duration_condition_enforces_policy_after_clamping() {
+        use rustfs_policy::policy::Policy;
+        let policy = Policy::parse_config(
+            br#"{"Version":"2012-10-17","Statement":[{
+            "Effect":"Deny","Action":"sts:AssumeRole","Resource":"*",
+            "Condition":{"NumericGreaterThan":{"sts:DurationSeconds":"3600"}}
+        }]}"#,
+        )
+        .expect("duration policy");
+        for (requested, allowed) in [(0, true), (1, true), (3600, true), (3601, false), (usize::MAX, false)] {
+            let mut conditions = HashMap::from([("DurationSeconds".to_string(), vec!["1".to_string()])]);
+            let lifetime = set_assume_role_duration_condition(&mut conditions, requested);
+            assert_eq!(conditions["DurationSeconds"], [lifetime.to_string()]);
+            assert_eq!(
+                policy
+                    .is_allowed(&Args {
+                        account: "user",
+                        groups: &None,
+                        action: Action::StsAction(StsAction::AssumeRoleAction),
+                        conditions: &conditions,
+                        is_owner: false,
+                        claims: &HashMap::new(),
+                        deny_only: true,
+                        bucket: "",
+                        object: "",
+                    })
+                    .await,
+                allowed,
+                "requested={requested}"
+            );
+        }
+    }
+
     #[test]
     fn test_assume_role_duration_is_clamped_to_max() {
         // Regression: the standard AssumeRole path previously used the raw client-supplied
diff --git a/rustfs/src/admin/handlers/table_catalog/mod.rs b/rustfs/src/admin/handlers/table_catalog/mod.rs
index ac1858e5b..c429835fa 100644
--- a/rustfs/src/admin/handlers/table_catalog/mod.rs
+++ b/rustfs/src/admin/handlers/table_catalog/mod.rs
@@ -24,7 +24,7 @@ use crate::admin::{
 };
 use crate::auth::{check_key_valid_with_context, get_session_token};
 use crate::error::ApiError;
-use crate::server::{RemoteAddr, TABLE_CATALOG_COMPAT_PREFIX, TABLE_CATALOG_PREFIX};
+use crate::server::{TABLE_CATALOG_COMPAT_PREFIX, TABLE_CATALOG_PREFIX};
 use crate::table_catalog::{DEFAULT_WAREHOUSE_ID, TableCatalogStore};
 use bytes::Bytes;
 use futures::{StreamExt, TryStreamExt, stream};
@@ -1141,7 +1141,7 @@ async fn authorize_table_catalog_request(req: &S3Request<Body>, action: AdminAct
         &principal.credentials,
         principal.owner,
         Action::AdminAction(action),
-        req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+        crate::admin::auth::policy_source_addr(&req.extensions),
         AdminResourceScope::bucket(""),
     )
     .await
@@ -1255,7 +1255,7 @@ async fn authorize_table_catalog_object_for_principal(
         &principal.credentials,
         principal.owner,
         Action::AdminAction(action),
-        req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+        crate::admin::auth::policy_source_addr(&req.extensions),
         AdminResourceScope::bucket_object(bucket, object),
     )
     .await
diff --git a/rustfs/src/admin/handlers/usage_prefix.rs b/rustfs/src/admin/handlers/usage_prefix.rs
index 7ef5003c0..59ea20b64 100644
--- a/rustfs/src/admin/handlers/usage_prefix.rs
+++ b/rustfs/src/admin/handlers/usage_prefix.rs
@@ -19,7 +19,7 @@
 //! usage caches, with a one-level sub-prefix breakdown — the data console
 //! buckets view MinIO serves from `loadPrefixUsageFromBackend`.
 
-use crate::admin::auth::authorize_admin_request;
+use crate::admin::auth::{authenticate_request, policy_source_addr, validate_admin_request_with_bucket};
 use crate::admin::handlers::system::data_usage_info_gate_actions;
 use crate::admin::router::{AdminOperation, Operation, S3Router};
 use crate::server::ADMIN_PREFIX;
@@ -69,15 +69,24 @@ fn parse_usage_prefix_query(query: Option<&str>) -> S3Result<(String, usize)> {
 #[async_trait::async_trait]
 impl Operation for BucketPrefixUsageHandler {
     async fn call(&self, req: S3Request<Body>, params: Params<'_, '_>) -> S3Result<S3Response<(StatusCode, Body)>> {
-        // The shared gate reports the same `InvalidRequest` "get cred failed" this
-        // handler has always returned for a credential-less request, so it needs no
-        // message-preserving pre-check.
-        authorize_admin_request(&req, data_usage_info_gate_actions()).await?;
-
+        let Some(input_cred) = req.credentials.as_ref() else {
+            return Err(S3Error::with_message(S3ErrorCode::InvalidRequest, "get cred failed"));
+        };
+        let (cred, owner) = authenticate_request(&req.headers, &req.uri, input_cred).await?;
         let bucket = params.get("bucket").unwrap_or_default().to_string();
         if bucket.is_empty() {
             return Err(s3_error!(InvalidRequest, "bucket path parameter is required"));
         }
+        validate_admin_request_with_bucket(
+            &req.headers,
+            &cred,
+            owner,
+            false,
+            data_usage_info_gate_actions(),
+            policy_source_addr(&req.extensions),
+            &bucket,
+        )
+        .await?;
         let (prefix, max_entries) = parse_usage_prefix_query(req.uri.query())?;
 
         // Authorization is bucket-scoped by the same any-of gate as the
diff --git a/rustfs/src/admin/handlers/user.rs b/rustfs/src/admin/handlers/user.rs
index 1d01339d2..3c3b8fc40 100644
--- a/rustfs/src/admin/handlers/user.rs
+++ b/rustfs/src/admin/handlers/user.rs
@@ -23,7 +23,6 @@ use crate::{
         utils::{encode_compatible_admin_payload, has_space_be, read_compatible_admin_body},
     },
     auth::{check_key_valid, constant_time_eq, get_session_token},
-    server::RemoteAddr,
 };
 use http::{HeaderMap, StatusCode};
 use matchit::Params;
@@ -31,7 +30,7 @@ use rustfs_config::{MAX_ADMIN_REQUEST_BODY_SIZE, MAX_IAM_IMPORT_EXPANDED_SIZE, M
 use rustfs_credentials::Credentials;
 use rustfs_iam::{
     store::{GroupInfo, MappedPolicy, UserType},
-    sys::{NewServiceAccountOpts, UpdateServiceAccountOpts},
+    sys::{NewServiceAccountOpts, SITE_REPLICATOR_SERVICE_ACCOUNT, UpdateServiceAccountOpts},
 };
 use rustfs_madmin::{
     AccountStatus, AddOrUpdateUserReq, IAMEntities, IAMErrEntities, IAMErrEntity, IAMErrPolicyEntity, SITE_REPL_API_VERSION,
@@ -196,6 +195,19 @@ fn imported_service_account_parent_scope_failure(
     })
 }
 
+fn retain_exportable_service_accounts(accounts: &mut HashMap<String, rustfs_policy::auth::UserIdentity>) {
+    accounts.retain(|key, account| {
+        key != SITE_REPLICATOR_SERVICE_ACCOUNT && account.credentials.access_key != SITE_REPLICATOR_SERVICE_ACCOUNT
+    });
+}
+
+fn imported_service_account_reserved_failure(access_key: &str) -> Option<IAMErrEntity> {
+    (access_key == SITE_REPLICATOR_SERVICE_ACCOUNT).then(|| IAMErrEntity {
+        name: access_key.to_owned(),
+        error: "service account name is reserved for site replication".to_owned(),
+    })
+}
+
 fn imported_service_account_access_key_failure(entry_access_key: &str, payload_access_key: &str) -> Option<IAMErrEntity> {
     (entry_access_key != payload_access_key).then(|| IAMErrEntity {
         name: entry_access_key.to_string(),
@@ -208,6 +220,7 @@ pub struct AddUser {}
 fn map_add_user_create_error(err: rustfs_iam::error::Error) -> S3Error {
     match err {
         rustfs_iam::error::Error::AccessKeyAlreadyExists => iam_error_to_s3_error(err),
+        rustfs_iam::error::Error::IAMActionNotAllowed => S3Error::new(S3ErrorCode::AccessDenied),
         err => S3Error::with_message(S3ErrorCode::InternalError, format!("failed to create user: {err}")),
     }
 }
@@ -243,7 +256,7 @@ impl Operation for AddUser {
         // let body_bytes = decrypt_data(input_cred.secret_key.expose().as_bytes(), &body)
         //     .map_err(|e| S3Error::with_message(S3ErrorCode::InvalidArgument, format!("decrypt_data err {}", e)))?;
 
-        let args: AddOrUpdateUserReq = serde_json::from_slice(&body)
+        let mut args: AddOrUpdateUserReq = serde_json::from_slice(&body)
             .map_err(|e| S3Error::with_message(S3ErrorCode::InvalidRequest, format!("invalid JSON: {e}")))?;
 
         if args.secret_key.is_empty() {
@@ -261,7 +274,7 @@ impl Operation for AddUser {
         };
 
         if let Some(user) = iam_store.get_user(ak).await {
-            if (user.credentials.is_temp() || user.credentials.is_service_account()) && cred.parent_user == ak {
+            if user.credentials.is_temp() || user.credentials.is_service_account() {
                 return Err(s3_error!(InvalidArgument, "cannot create a user with a service account access key"));
             }
         } else if has_space_be(ak) {
@@ -306,11 +319,22 @@ impl Operation for AddUser {
             owner,
             check_deny_only,
             vec![Action::AdminAction(AdminAction::CreateUserAdminAction)],
-            req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+            crate::admin::auth::policy_source_addr(&req.extensions),
         )
         .await?;
 
-        let updated_at = iam_store.create_user(ak, &args).await.map_err(map_add_user_create_error)?;
+        let updated_at = if check_deny_only {
+            let (updated_at, status, _) = iam_store
+                .change_own_secret_key(ak, input_cred.secret_key.expose(), &args.secret_key)
+                .await
+                .map_err(map_add_user_create_error)?;
+            args.status = status;
+            // A self-service secret rotation does not change policy attachment.
+            args.policy = None;
+            updated_at
+        } else {
+            iam_store.create_user(ak, &args).await.map_err(map_add_user_create_error)?
+        };
 
         if let Err(err) = site_replication_iam_change_hook(SRIAMItem {
             r#type: "iam-user".to_string(),
@@ -619,7 +643,7 @@ impl Operation for GetUserInfo {
             owner,
             check_deny_only,
             vec![Action::AdminAction(AdminAction::GetUserAdminAction)],
-            req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+            crate::admin::auth::policy_source_addr(&req.extensions),
         )
         .await?;
 
@@ -749,12 +773,9 @@ impl Operation for ExportIam {
                         .await
                         .map_err(|e| S3Error::with_message(S3ErrorCode::InternalError, e.to_string()))?;
 
+                    retain_exportable_service_accounts(&mut service_accounts);
                     let mut svc_accts: HashMap<String, SRSvcAccCreate> = HashMap::new();
                     for (k, acc) in service_accounts {
-                        if k == "siteReplicatorSvcAcc" {
-                            continue;
-                        }
-
                         let claims = iam_store
                             .get_claims_for_svc_acc(&acc.credentials.access_key)
                             .await
@@ -904,7 +925,7 @@ impl Operation for ImportIam {
             owner,
             false,
             vec![Action::AdminAction(AdminAction::ImportIAMAction)],
-            req.extensions.get::<Option<RemoteAddr>>().and_then(|opt| opt.map(|a| a.0)),
+            crate::admin::auth::policy_source_addr(&req.extensions),
         )
         .await?;
 
@@ -1089,6 +1110,11 @@ impl Operation for ImportIam {
                         return Err(s3_error!(InvalidArgument, "has space be {ak}"));
                     }
 
+                    if let Some(err) = imported_service_account_reserved_failure(&ak) {
+                        failed.service_accounts.push(err);
+                        continue;
+                    }
+
                     if let Some(err) = imported_service_account_access_key_failure(&ak, &req.access_key) {
                         failed.service_accounts.push(err);
                         continue;
@@ -1463,6 +1489,74 @@ mod tests {
         }
     }
 
+    #[test]
+    fn iam_export_excludes_site_replicator_credentials() {
+        let mut accounts = HashMap::from([
+            (
+                "site-replicator-0".to_owned(),
+                rustfs_policy::auth::UserIdentity::new(Credentials {
+                    access_key: "site-replicator-0".to_owned(),
+                    secret_key: "replicator-secret".to_owned(),
+                    ..Default::default()
+                }),
+            ),
+            (
+                "ordinary-service".to_owned(),
+                rustfs_policy::auth::UserIdentity::new(Credentials {
+                    access_key: "ordinary-service".to_owned(),
+                    secret_key: "ordinary-secret".to_owned(),
+                    ..Default::default()
+                }),
+            ),
+            (
+                "mismatched-entry".to_owned(),
+                rustfs_policy::auth::UserIdentity::new(Credentials {
+                    access_key: "site-replicator-0".to_owned(),
+                    secret_key: "aliased-replicator-secret".to_owned(),
+                    ..Default::default()
+                }),
+            ),
+        ]);
+        super::retain_exportable_service_accounts(&mut accounts);
+        assert_eq!(accounts.len(), 1);
+        assert_eq!(accounts["ordinary-service"].credentials.secret_key, "ordinary-secret");
+        let exported = serde_json::to_string(&accounts).expect("serialize selected export records");
+        assert!(!exported.contains("replicator"));
+    }
+
+    #[test]
+    fn iam_archives_preserve_the_reserved_site_replicator_identity() {
+        let failure = super::imported_service_account_reserved_failure(rustfs_iam::sys::SITE_REPLICATOR_SERVICE_ACCOUNT)
+            .expect("the site replicator must never be replaced by an IAM import");
+        assert_eq!(failure.name, "site-replicator-0");
+        assert_eq!(failure.error, "service account name is reserved for site replication");
+        assert!(super::imported_service_account_reserved_failure("ordinary-service-account").is_none());
+        let source = include_str!("user.rs")
+            .split("\n#[cfg(test)]\n")
+            .next()
+            .expect("production source");
+        let export = source_block(source, "impl Operation for ExportIam");
+        let guard = export
+            .find("retain_exportable_service_accounts(&mut service_accounts)")
+            .expect("export uses the canonical reserved identity");
+        assert!(
+            guard
+                < export
+                    .find("let svc_acc_create_req = SRSvcAccCreate")
+                    .expect("exported credentials")
+        );
+        let import = source_block(source, "impl Operation for ImportIam");
+        let guard = import
+            .find("imported_service_account_reserved_failure(&ak)")
+            .expect("import rejects the reserved identity");
+        assert!(
+            guard
+                < import
+                    .find(".delete_service_account(&ak")
+                    .expect("replacement deletes the original account")
+        );
+    }
+
     #[test]
     fn import_iam_enqueues_a_site_replication_snapshot() {
         let body = source_block(include_str!("user.rs"), "impl Operation for ImportIam");
diff --git a/rustfs/src/admin/route_policy.rs b/rustfs/src/admin/route_policy.rs
index d4c1ae568..13a555a1c 100644
--- a/rustfs/src/admin/route_policy.rs
+++ b/rustfs/src/admin/route_policy.rs
@@ -18,7 +18,6 @@ use rustfs_security_governance::{
 };
 
 const ALL_ADMIN: AdminActionRef = AdminActionRef::new("AllAdminActions");
-const ADD_USER_TO_GROUP: AdminActionRef = AdminActionRef::new("AddUserToGroupAdminAction");
 const ATTACH_POLICY: AdminActionRef = AdminActionRef::new("AttachPolicyAdminAction");
 const CONFIG_UPDATE: AdminActionRef = AdminActionRef::new("ConfigUpdateAdminAction");
 const TLS_CERTIFICATE_PUBLISH: AdminActionRef = AdminActionRef::new("TLSCertificatePublishAdminAction");
@@ -187,12 +186,6 @@ pub const ADMIN_ROUTE_POLICY_SPECS: &[AdminRouteSpec] = &[
         RouteRiskLevel::High,
     ),
     admin(HttpMethod::Put, "/rustfs/admin/v3/set-group-status", ENABLE_GROUP, RouteRiskLevel::High),
-    admin(
-        HttpMethod::Put,
-        "/rustfs/admin/v3/update-group-members",
-        ADD_USER_TO_GROUP,
-        RouteRiskLevel::High,
-    ),
     admin(
         HttpMethod::Get,
         "/rustfs/admin/v3/temporary-account-info",
@@ -1806,6 +1799,11 @@ pub const ADMIN_ROUTE_POLICY_SPECS: &[AdminRouteSpec] = &[
 ];
 
 pub const DEFERRED_ADMIN_ROUTE_POLICIES: &[DeferredAdminRoutePolicy] = &[
+    deferred(
+        HttpMethod::Put,
+        "/rustfs/admin/v3/update-group-members",
+        DeferredRoutePolicyReason::MultipleActions,
+    ),
     deferred(HttpMethod::Get, "/rustfs/admin/v3/accountinfo", DeferredRoutePolicyReason::S3Action),
     // The self-service account routes act on the caller, never on a target
     // named in the request, so they gate on possession of the credential (plus,
diff --git a/rustfs/src/admin/service/federated_identity.rs b/rustfs/src/admin/service/federated_identity.rs
index 1641a9447..c8d7090e8 100644
--- a/rustfs/src/admin/service/federated_identity.rs
+++ b/rustfs/src/admin/service/federated_identity.rs
@@ -20,7 +20,7 @@ use crate::admin::{
 use rustfs_iam::{
     federation::{FederatedSessionBinding, FederatedSessionBindingError, FederatedSessionTransaction, OIDC_VIRTUAL_PARENT_CLAIM},
     store::{MappedPolicy, object::ObjectStore},
-    sys::{IamSys, is_safe_claim_policy_name},
+    sys::{IamSys, OIDC_ISSUER_CLAIM, is_safe_claim_policy_name},
 };
 use rustfs_madmin::{SITE_REPL_API_VERSION, SR_IAM_ITEM_STS_ACC, SRIAMItem, SRSTSCredential};
 use rustfs_policy::auth::get_new_credentials_with_metadata;
@@ -111,6 +111,9 @@ fn build_oidc_token_claims(transaction: &FederatedSessionTransaction) -> HashMap
     let mut token_claims = HashMap::new();
     token_claims.insert("sub".to_string(), Value::String(authorization.subject().to_string()));
     token_claims.insert("iss".to_string(), Value::String("rustfs-oidc".to_string()));
+    if let Some(issuer) = authorization.issuer() {
+        token_claims.insert(OIDC_ISSUER_CLAIM.to_string(), Value::String(issuer.to_string()));
+    }
     token_claims.insert("oidc_provider".to_string(), Value::String(authorization.provider_id().to_string()));
 
     if !authorization.email().is_empty() {
@@ -329,14 +332,31 @@ impl FederatedSessionBinding for DefaultFederatedSessionBinding {
         let parent_user = authorization.oidc_virtual_parent().ok_or_else(|| {
             FederatedSessionBindingError::InvalidRequest("verified OIDC identity is missing issuer or subject".to_string())
         })?;
-        let (selected_policy_names, ignorable_policy_names) = match iam_store
-            .sts_policy_db_get(&parent_user, &Some(authorization.mapped_iam_groups().to_vec()))
+        let (mapped_policy_names, has_identity_mapping) = iam_store
+            .sts_policy_db_get_with_identity_mapping(&parent_user, &Some(authorization.mapped_iam_groups().to_vec()))
             .await
-            .map_err(|_| FederatedSessionBindingError::Internal("failed to resolve OIDC policy mapping".to_string()))?
-        {
-            mapped_policy_names if !mapped_policy_names.is_empty() => (mapped_policy_names, &[][..]),
-            _ => (authorization.policies().to_vec(), authorization.group_claim_policies()),
+            .map_err(|_| FederatedSessionBindingError::Internal("failed to resolve OIDC policy mapping".to_string()))?;
+        // An explicit identity mapping overrides token policies. Group mappings
+        // are additive and must not discard claim-derived Deny policies.
+        let ignorable_policy_names: Vec<String> = if has_identity_mapping {
+            Vec::new()
+        } else {
+            authorization
+                .group_claim_policies()
+                .iter()
+                .filter(|name| !mapped_policy_names.contains(name))
+                .cloned()
+                .collect()
         };
+        let mut selected_policy_names = mapped_policy_names;
+        if !has_identity_mapping {
+            for name in authorization.policies() {
+                if !selected_policy_names.contains(name) {
+                    selected_policy_names.push(name.clone());
+                }
+            }
+        }
+
         // A name may be skipped only after storage confirms the policy is absent. A failed lookup
         // must not be mistaken for absence, or an unreadable Deny policy would be dropped from the
         // signed session and could not be restored at request time.
@@ -368,7 +388,7 @@ impl FederatedSessionBinding for DefaultFederatedSessionBinding {
         let resolved_policy_names = MappedPolicy::new(&resolved_policy_mapping).to_slice();
         let selection = select_oidc_policies(
             &selected_policy_names,
-            ignorable_policy_names,
+            &ignorable_policy_names,
             &resolved_policy_names,
             &missing_policy_names,
         )
@@ -543,6 +563,7 @@ mod tests {
             HashMap::from([
                 ("sub".to_string(), serde_json::json!("subject")),
                 ("iss".to_string(), serde_json::json!("rustfs-oidc")),
+                (OIDC_ISSUER_CLAIM.to_string(), serde_json::json!("https://idp.example.test")),
                 ("oidc_provider".to_string(), serde_json::json!("default")),
                 ("email".to_string(), serde_json::json!("user@example.com")),
                 ("preferred_username".to_string(), serde_json::json!("user")),
@@ -566,6 +587,7 @@ mod tests {
             HashMap::from([
                 ("sub".to_string(), serde_json::json!("subject")),
                 ("iss".to_string(), serde_json::json!("rustfs-oidc")),
+                (OIDC_ISSUER_CLAIM.to_string(), serde_json::json!("https://idp.example.test")),
                 ("oidc_provider".to_string(), serde_json::json!("default")),
             ])
         );
@@ -641,6 +663,7 @@ mod tests {
             HashMap::from([
                 ("sub".to_string(), serde_json::json!("subject")),
                 ("iss".to_string(), serde_json::json!("rustfs-oidc")),
+                (OIDC_ISSUER_CLAIM.to_string(), serde_json::json!("https://idp.example.test")),
                 ("oidc_provider".to_string(), serde_json::json!("default")),
                 ("email".to_string(), serde_json::json!("user@example.com")),
                 ("preferred_username".to_string(), serde_json::json!("user")),
@@ -684,6 +707,153 @@ mod tests {
         );
     }
 
+    #[tokio::test]
+    #[serial]
+    async fn binding_group_policies_preserve_claim_denies() {
+        let iam = ready_test_iam().await;
+        let deny = Policy::parse_config(
+            br#"{"Version":"2012-10-17","Statement":[{
+            "Effect":"Deny","Action":"s3:GetObject","Resource":"arn:aws:s3:::payroll/*"
+        }]}"#,
+        )
+        .expect("parse payroll Deny");
+        iam.set_policy("claim-deny-payroll", deny).await.expect("store claim Deny");
+        iam.add_users_to_group("claim-policy-group", Vec::new())
+            .await
+            .expect("create mapped group");
+        iam.policy_db_set("claim-policy-group", UserType::Reg, true, "readwrite")
+            .await
+            .expect("attach group Allow");
+        let authorization = || {
+            let mut fixture = authorization_fixture();
+            fixture.sub = "claim-deny-subject".to_string();
+            fixture.policies = vec!["readwrite".to_string(), "claim-deny-payroll".to_string()];
+            fixture.mapped_iam_groups = vec!["claim-policy-group".to_string()];
+            fixture
+        };
+        let credentials = DefaultFederatedSessionBinding
+            .bind(&transaction_from_fixture(authorization()))
+            .await
+            .expect("bind group plus claim policies");
+        let claims = get_claims_for_test(&credentials);
+        let selected = MappedPolicy::new(claims.get("policy").and_then(Value::as_str).expect("policy claim")).to_slice();
+        assert!(selected.contains(&"claim-deny-payroll".to_string()));
+        let conditions = HashMap::new();
+        let args = Args {
+            account: &credentials.access_key,
+            groups: &credentials.groups,
+            action: Action::S3Action(S3Action::GetObjectAction),
+            bucket: "payroll",
+            object: "salary.csv",
+            conditions: &conditions,
+            claims: &claims,
+            is_owner: false,
+            deny_only: false,
+        };
+        assert!(!iam.is_allowed(&args).await, "group Allow must not discard claim Deny");
+        let mut authorization = authorization();
+        authorization.policies.push("missing-required-policy".to_string());
+        assert!(
+            DefaultFederatedSessionBinding
+                .bind(&transaction_from_fixture(authorization))
+                .await
+                .is_err(),
+            "group mappings must not hide unresolved required claim policies"
+        );
+    }
+
+    fn get_claims_for_test(credentials: &rustfs_credentials::Credentials) -> HashMap<String, Value> {
+        let signing_key = current_token_signing_key().expect("test signing key");
+        rustfs_iam::sys::get_claims_from_token_with_secret(&credentials.session_token, &signing_key)
+            .expect("verify issued session token")
+    }
+
+    #[tokio::test]
+    #[serial]
+    async fn group_conditions_follow_live_parent_membership_for_all_credentials() {
+        let iam = ready_test_iam().await;
+        let user = "live-group-condition-user";
+        let group = "live-restricted-group";
+        iam.create_user(
+            user,
+            &AddOrUpdateUserReq {
+                secret_key: "live-group-user-secret".to_string(),
+                policy: None,
+                status: AccountStatus::Enabled,
+            },
+        )
+        .await
+        .expect("create group condition user");
+        let policy = Policy::parse_config(
+            br#"{"Version":"2012-10-17","Statement":[
+            {"Effect":"Allow","Action":"s3:GetObject","Resource":"arn:aws:s3:::bucket/*"},
+            {"Effect":"Deny","Action":"s3:GetObject","Resource":"arn:aws:s3:::bucket/*",
+             "Condition":{"StringEquals":{"aws:groups":"live-restricted-group"}}}
+        ]}"#,
+        )
+        .expect("parse group condition policy");
+        for member in [true, false, true] {
+            if member {
+                iam.add_users_to_group(group, vec![user.to_string()])
+                    .await
+                    .expect("add membership");
+            } else {
+                iam.remove_users_from_group(group, vec![user.to_string()])
+                    .await
+                    .expect("remove membership");
+            }
+            for kind in ["regular", "sts", "service"] {
+                let mut credentials = rustfs_credentials::Credentials {
+                    access_key: if kind == "regular" {
+                        user
+                    } else {
+                        "derived-group-condition-key"
+                    }
+                    .to_string(),
+                    secret_key: "valid-derived-secret".to_string(),
+                    status: "on".to_string(),
+                    groups: Some(vec!["credential-group".to_string()]),
+                    ..Default::default()
+                };
+                if kind != "regular" {
+                    credentials.parent_user = user.to_string();
+                    credentials.session_token = "signed-token".to_string();
+                }
+                credentials.claims = Some(HashMap::from([("groups".to_string(), serde_json::json!(["token-group"]))]));
+                if kind == "service" {
+                    credentials
+                        .claims
+                        .as_mut()
+                        .expect("claims")
+                        .insert("sa-policy".to_string(), serde_json::json!("inherited-policy"));
+                }
+                let conditions = crate::auth::get_condition_values(&http::HeaderMap::new(), &credentials, None, None, None);
+                let groups = conditions.get("groups").expect("credential and token groups");
+                assert!(groups.contains(&"token-group".to_string()));
+                assert!(groups.contains(&"credential-group".to_string()));
+                assert_eq!(groups.contains(&group.to_string()), member, "{kind}");
+                let claims = HashMap::new();
+                assert_eq!(
+                    policy
+                        .is_allowed(&Args {
+                            account: &credentials.access_key,
+                            groups: &credentials.groups,
+                            action: Action::S3Action(S3Action::GetObjectAction),
+                            bucket: "bucket",
+                            object: "object",
+                            conditions: &conditions,
+                            claims: &claims,
+                            is_owner: false,
+                            deny_only: false,
+                        })
+                        .await,
+                    !member,
+                    "{kind}"
+                );
+            }
+        }
+    }
+
     #[tokio::test]
     #[serial]
     async fn binding_uses_sts_policy_when_regular_mapping_collides() {
diff --git a/rustfs/src/auth.rs b/rustfs/src/auth.rs
index a7fbc13cb..ed1effd36 100644
--- a/rustfs/src/auth.rs
+++ b/rustfs/src/auth.rs
@@ -19,7 +19,8 @@ use http::header::{IF_MATCH, IF_NONE_MATCH};
 use rustfs_credentials::Credentials;
 use rustfs_iam::error::Error as IamError;
 use rustfs_iam::sys::{
-    SESSION_POLICY_NAME, get_claims_from_token_with_secret, get_claims_from_token_with_secret_allow_missing_exp,
+    OIDC_ISSUER_CLAIM, SESSION_POLICY_NAME, get_claims_from_token_with_secret,
+    get_claims_from_token_with_secret_allow_missing_exp, is_rustfs_oidc_claims,
 };
 use rustfs_policy::policy::{ClaimLookup, get_claim_case_insensitive, is_server_derived_condition_key};
 use rustfs_trusted_proxies::ClientInfo;
@@ -801,6 +802,17 @@ pub fn get_condition_values_with_query_and_client_info(
             }
         }
 
+        if is_rustfs_oidc_claims(claims) {
+            args.remove("iss");
+            if let Some(issuer) = claims
+                .get(OIDC_ISSUER_CLAIM)
+                .and_then(Value::as_str)
+                .filter(|issuer| !issuer.is_empty())
+            {
+                args.insert("iss".to_string(), vec![issuer.to_string()]);
+            }
+        }
+
         let grps = extract_string_list_claim(claims, "groups");
         if !grps.is_empty() {
             args.insert("groups".to_string(), grps);
@@ -812,10 +824,19 @@ pub fn get_condition_values_with_query_and_client_info(
         }
     }
 
-    if let Some(groups) = &cred.groups
-        && !args.contains_key("groups")
-    {
-        args.insert("groups".to_string(), groups.clone());
+    let effective_user = if (cred.is_service_account() || cred.is_temp()) && !cred.parent_user.is_empty() {
+        &cred.parent_user
+    } else {
+        &cred.access_key
+    };
+    let live_groups = current_ready_iam_handle()
+        .map(|iam| iam.user_group_memberships(effective_user))
+        .unwrap_or_default();
+    for group in cred.groups.iter().flatten().chain(live_groups.iter()) {
+        let groups = args.entry("groups".to_string()).or_default();
+        if !groups.contains(group) {
+            groups.push(group.clone());
+        }
     }
 
     // Every remaining header is attacker-controlled. A header must never contribute
@@ -2305,6 +2326,56 @@ mod tests {
         // (we can't directly test this without changing the function signature)
     }
 
+    #[tokio::test]
+    async fn oidc_issuer_condition_uses_verified_provider_not_session_marker_or_header() {
+        use rustfs_policy::policy::{
+            Args, Policy,
+            action::{Action, S3Action},
+        };
+
+        let policy = Policy::parse_config(
+            br#"{"Version":"2012-10-17","Statement":[
+                {"Effect":"Allow","Action":"s3:GetObject","Resource":"arn:aws:s3:::bucket/*"},
+                {"Effect":"Deny","Action":"s3:GetObject","Resource":"arn:aws:s3:::bucket/*",
+                 "Condition":{"StringEquals":{"jwt:iss":"https://partner.example"}}}
+            ]}"#,
+        )
+        .expect("parse issuer condition");
+        let mut credentials = create_test_credentials();
+        let mut headers = HeaderMap::new();
+        headers.insert("iss", HeaderValue::from_static("https://spoofed.invalid"));
+        headers.insert(OIDC_ISSUER_CLAIM, HeaderValue::from_static("https://spoofed.invalid"));
+        for issuer in [Some("https://partner.example"), Some("https://corporate.example"), None] {
+            let mut claims = HashMap::from([
+                ("iss".to_string(), json!("rustfs-oidc")),
+                ("oidc_provider".to_string(), json!("provider")),
+                ("sub".to_string(), json!("subject")),
+            ]);
+            if let Some(issuer) = issuer {
+                claims.insert(OIDC_ISSUER_CLAIM.to_string(), json!(issuer));
+            }
+            credentials.claims = Some(claims);
+            let conditions = get_condition_values(&headers, &credentials, None, None, None);
+            assert_eq!(conditions.get("iss"), issuer.map(|value| vec![value.to_string()]).as_ref());
+            assert_eq!(
+                policy
+                    .is_allowed(&Args {
+                        account: &credentials.access_key,
+                        groups: &credentials.groups,
+                        action: Action::S3Action(S3Action::GetObjectAction),
+                        bucket: "bucket",
+                        object: "object",
+                        conditions: &conditions,
+                        claims: credentials.claims_or_empty(),
+                        is_owner: false,
+                        deny_only: false,
+                    })
+                    .await,
+                issuer != Some("https://partner.example"),
+            );
+        }
+    }
+
     #[test]
     fn test_get_condition_values_with_claims() {
         let mut cred = create_service_account_credentials();