diff --git a/crates/targets/src/store.rs b/crates/targets/src/store.rs
index 4a19295ae..0a98524c5 100644
--- a/crates/targets/src/store.rs
+++ b/crates/targets/src/store.rs
@@ -919,6 +919,22 @@ where
             }
         }
 
+        // The filename's item count is untrusted. Reject a payload that contains
+        // more items than advertised instead of returning success and allowing the
+        // caller to delete the entry with trailing events still in the file.
+        match deserializer.next() {
+            None => {}
+            Some(Ok(_)) => {
+                return Err(StoreError::Deserialization(format!(
+                    "Batch for key {key} contains more than {} items",
+                    key.item_count
+                )));
+            }
+            Some(Err(e)) => {
+                return Err(StoreError::Deserialization(format!("Failed to deserialize trailing batch item: {e}")));
+            }
+        }
+
         if items.is_empty() && key.item_count > 0 {
             return Err(StoreError::Deserialization("No items found".to_string()));
         }
@@ -1381,6 +1397,39 @@ mod tests {
         let _ = store.delete();
     }
 
+    #[test]
+    fn get_multiple_errors_on_batch_with_trailing_items_instead_of_partial_success() {
+        let dir = temp_store_dir("trailing-batch-items");
+        let store = QueueStore::<String>::new_with_compression(&dir, 8, ".test", false);
+        store.open().unwrap();
+
+        let items = vec!["aa".to_string(), "bb".to_string(), "cc".to_string()];
+        let original_key = store.put_multiple(items).unwrap();
+        assert_eq!(original_key.item_count, 3);
+
+        // Keep the three-item payload but make its filename claim that it contains
+        // only two items, simulating a corrupt or otherwise untrusted queue key.
+        let original_path = store.file_path(&original_key);
+        let advertised_key = Key {
+            item_count: 2,
+            ..original_key
+        };
+        let advertised_path = store.file_path(&advertised_key);
+        std::fs::rename(&original_path, &advertised_path).unwrap();
+
+        let err = store.get_multiple(&advertised_key).unwrap_err();
+        assert!(
+            matches!(err, StoreError::Deserialization(_)),
+            "expected Deserialization error, got {err:?}"
+        );
+
+        // Because get_multiple failed, the batch entry remains available for
+        // inspection or recovery instead of being silently discarded.
+        assert!(advertised_path.exists());
+
+        let _ = store.delete();
+    }
+
     #[test]
     fn concurrent_put_raw_respects_entry_limit() {
         let dir = temp_store_dir("concurrent-limit");
diff --git a/docs/testing/ci-gates.md b/docs/testing/ci-gates.md
index 20874320f..2635367e0 100644
--- a/docs/testing/ci-gates.md
+++ b/docs/testing/ci-gates.md
@@ -286,6 +286,8 @@ workflow, builds the current checkout, runs the mixed-version and rollback E2E
 lanes, and fails unless all three raw G09 artifacts are measured, revision-bound,
 and role-bound. Use `--source-binary` for a custom previous-release binary on
 another platform, or `--test mixed-version|rollback` while narrowing a failure.
+It performs a free-space preflight before building so a saturated validation
+host fails before producing partial evidence.
 
 When the real release lanes have produced their dedicated artifacts, validate
 the complete hard-gate bundle with:
diff --git a/scripts/run_scanner_heal_g09_upgrade_evidence.sh b/scripts/run_scanner_heal_g09_upgrade_evidence.sh
index 2be5a6e28..4c3efd01b 100755
--- a/scripts/run_scanner_heal_g09_upgrade_evidence.sh
+++ b/scripts/run_scanner_heal_g09_upgrade_evidence.sh
@@ -8,6 +8,7 @@ SOURCE_REPOSITORY="${RUSTFS_UPGRADE_SOURCE_REPOSITORY:-rustfs/rustfs}"
 SOURCE_VERSION="${RUSTFS_UPGRADE_SOURCE_VERSION:-1.0.0-rc.5}"
 SOURCE_ASSET="${RUSTFS_UPGRADE_SOURCE_ASSET:-rustfs-linux-x86_64-gnu-v1.0.0-rc.5.zip}"
 SOURCE_SHA256="${RUSTFS_UPGRADE_SOURCE_SHA256:-3ee8df71e8edcfada533be452c4135868f697bc515460ae97b027313eade7a3d}"
+MIN_FREE_KIB="${RUSTFS_G09_MIN_FREE_KIB:-6291456}"
 
 RUN_DIR=""
 SOURCE_DIR=""
@@ -39,7 +40,9 @@ Options:
   -h, --help         Show this help
 
 The default pinned release asset is Linux x86_64. Use --source-binary when
-running against a custom previous-release binary on another platform.
+running against a custom previous-release binary on another platform. The
+script requires at least 6 GiB free by default; override
+RUSTFS_G09_MIN_FREE_KIB only for a deliberately smaller diagnostic run.
 USAGE
 }
 
@@ -122,6 +125,21 @@ verify_sha256() {
     fi
 }
 
+ensure_min_free_space() {
+    local path="$1"
+    local available
+    mkdir -p "$path"
+    available="$(df -Pk "$path" | awk 'NR == 2 { print $4 }')"
+    if [[ -z "$available" ]]; then
+        echo "could not determine free space for $path" >&2
+        exit 1
+    fi
+    if (( available < MIN_FREE_KIB )); then
+        echo "insufficient free space for G09 evidence run at $path: need ${MIN_FREE_KIB} KiB, found ${available} KiB" >&2
+        exit 1
+    fi
+}
+
 resolve_source_binary() {
     if [[ -n "$SOURCE_BINARY" ]]; then
         SOURCE_BINARY="$(normalize_path "$SOURCE_BINARY")"
@@ -326,6 +344,7 @@ if [[ "$PLAN_ONLY" == 1 ]]; then
     echo "tests=${CASES[*]}"
     echo "source_repository=$SOURCE_REPOSITORY"
     echo "source_version=$SOURCE_VERSION"
+    echo "min_free_kib=$MIN_FREE_KIB"
     if [[ -n "$SOURCE_BINARY" ]]; then
         echo "source_binary=$(normalize_path "$SOURCE_BINARY")"
     else
@@ -349,6 +368,11 @@ if [[ -e "$RUN_DIR" ]]; then
     exit 1
 fi
 mkdir -p "$RUN_DIR/logs"
+if [[ -n "${TMPDIR:-}" ]]; then
+    mkdir -p "$TMPDIR"
+    ensure_min_free_space "$TMPDIR"
+fi
+ensure_min_free_space "$RUN_DIR"
 
 SOURCE_BINARY="$(resolve_source_binary)"
 export RUSTFS_UPGRADE_SOURCE_BINARY="$SOURCE_BINARY"