diff --git a/Cargo.lock b/Cargo.lock
index 952c18d1e..1ea5ef359 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -7601,6 +7601,7 @@ dependencies = [
  "mime_guess",
  "moka",
  "opentelemetry",
+ "percent-encoding",
  "pin-project-lite",
  "pprof-pyroscope-fork",
  "rand 0.10.0",
diff --git a/rustfs/Cargo.toml b/rustfs/Cargo.toml
index 17c182df6..61871a403 100644
--- a/rustfs/Cargo.toml
+++ b/rustfs/Cargo.toml
@@ -127,6 +127,7 @@ matchit = { workspace = true }
 md5.workspace = true
 mime_guess = { workspace = true }
 moka = { workspace = true }
+percent-encoding = { workspace = true }
 pin-project-lite.workspace = true
 rust-embed = { workspace = true, features = ["interpolate-folder-path"] }
 s3s.workspace = true
diff --git a/rustfs/src/admin/handlers/kms_keys.rs b/rustfs/src/admin/handlers/kms_keys.rs
index bee73bc6a..aa154ee6b 100644
--- a/rustfs/src/admin/handlers/kms_keys.rs
+++ b/rustfs/src/admin/handlers/kms_keys.rs
@@ -302,6 +302,24 @@ mod tests {
             assert_eq!(extract_key_id(&uri).as_deref(), Some(expected));
         }
     }
+
+    #[test]
+    fn test_extract_key_id_skips_empty_values_and_uses_next_alias() {
+        let uri: Uri = "/rustfs/admin/v3/kms/key/status?keyId=&key-id=minio-key&key=fallback-key"
+            .parse()
+            .expect("uri should parse");
+
+        assert_eq!(extract_key_id(&uri).as_deref(), Some("minio-key"));
+    }
+
+    #[test]
+    fn test_extract_key_id_prefers_legacy_name_over_aliases() {
+        let uri: Uri = "/rustfs/admin/v3/kms/key/status?keyId=legacy-key&key-id=minio-key&key=fallback-key"
+            .parse()
+            .expect("uri should parse");
+
+        assert_eq!(extract_key_id(&uri).as_deref(), Some("legacy-key"));
+    }
 }
 
 /// List KMS keys (legacy endpoint)
diff --git a/rustfs/src/admin/handlers/tier.rs b/rustfs/src/admin/handlers/tier.rs
index 11b61760f..689b79e85 100644
--- a/rustfs/src/admin/handlers/tier.rs
+++ b/rustfs/src/admin/handlers/tier.rs
@@ -26,6 +26,7 @@ use http::Uri;
 use http::{HeaderMap, StatusCode};
 use hyper::Method;
 use matchit::Params;
+use percent_encoding::percent_decode_str;
 use rustfs_common::data_usage::TierStats;
 use rustfs_config::MAX_ADMIN_REQUEST_BODY_SIZE;
 use rustfs_ecstore::bucket::lifecycle::bucket_lifecycle_ops::GLOBAL_TransitionState;
@@ -83,8 +84,14 @@ pub struct AddTierQuery {
 pub struct AddTier {}
 
 fn resolve_tier_name(uri: &Uri, params: &Params<'_, '_>) -> S3Result<String> {
-    if let Some(tier) = params.get("tier").map(str::trim).filter(|tier| !tier.is_empty()) {
-        return Ok(tier.to_string());
+    if let Some(tier) = params.get("tier") {
+        let decoded = percent_decode_str(tier)
+            .decode_utf8()
+            .map_err(|_| s3_error!(InvalidArgument, "invalid tier path parameter"))?;
+        let trimmed = decoded.trim();
+        if !trimmed.is_empty() {
+            return Ok(trimmed.to_string());
+        }
     }
 
     let query = if let Some(query) = uri.query() {
@@ -712,6 +719,46 @@ mod tests {
         assert_eq!(tier, "WARM");
     }
 
+    #[test]
+    fn resolve_tier_name_falls_back_when_path_parameter_is_blank() {
+        let uri: Uri = "/rustfs/admin/v3/tier/%20?tier=WARM".parse().expect("uri should parse");
+        let mut router = Router::new();
+        router
+            .insert("/rustfs/admin/v3/tier/{tier}", ())
+            .expect("route should insert");
+        let matched = router.at("/rustfs/admin/v3/tier/%20").expect("route should match");
+
+        let tier = resolve_tier_name(&uri, &matched.params).expect("query parameter should resolve");
+        assert_eq!(tier, "WARM");
+    }
+
+    #[test]
+    fn resolve_tier_name_preserves_plus_in_path_parameter() {
+        let uri: Uri = "/rustfs/admin/v3/tier/WARM+PLUS".parse().expect("uri should parse");
+        let mut router = Router::new();
+        router
+            .insert("/rustfs/admin/v3/tier/{tier}", ())
+            .expect("route should insert");
+        let matched = router.at("/rustfs/admin/v3/tier/WARM+PLUS").expect("route should match");
+
+        let tier = resolve_tier_name(&uri, &matched.params).expect("path parameter should resolve");
+        assert_eq!(tier, "WARM+PLUS");
+    }
+
+    #[test]
+    fn resolve_tier_name_rejects_blank_path_without_query_fallback() {
+        let uri: Uri = "/rustfs/admin/v3/tier/%20".parse().expect("uri should parse");
+        let mut router = Router::new();
+        router
+            .insert("/rustfs/admin/v3/tier/{tier}", ())
+            .expect("route should insert");
+        let matched = router.at("/rustfs/admin/v3/tier/%20").expect("route should match");
+
+        let err = resolve_tier_name(&uri, &matched.params).expect_err("blank path should fail");
+        assert_eq!(err.code(), &S3ErrorCode::InvalidArgument);
+        assert_eq!(err.message(), Some("tier is required"));
+    }
+
     #[test]
     fn require_tier_name_rejects_missing_value() {
         let err = require_tier_name(&AddTierQuery::default()).expect_err("missing tier should return an error");