# UNDF: UNDF-2026-000000193
--- a/OgreMain/include/OgreNode.h
+++ b/OgreMain/include/OgreNode.h
@@ -28,6 +28,7 @@
 #ifndef _Node_H__
 #define _Node_H__

+#include <unordered_set>
 #include "OgrePrerequisites.h"

 #include "OgreMatrix4.h"
@@ -190,7 +191,7 @@ namespace Ogre {
         /** Queue of nodes pending update. */
-        typedef std::vector<Node*> QueuedUpdates;
+        typedef std::unordered_set<Node*> QueuedUpdates;
         static QueuedUpdates msQueuedUpdates;

--- a/OgreMain/src/OgreNode.cpp
+++ b/OgreMain/src/OgreNode.cpp
@@ -71,12 +71,9 @@ namespace Ogre {
         if (mQueuedForUpdate)
         {
-            // Erase from queued updates
-            QueuedUpdates::iterator it =
-                std::find(msQueuedUpdates.begin(), msQueuedUpdates.end(), this);
-            assert(it != msQueuedUpdates.end());
-            if (it != msQueuedUpdates.end())
-            {
-                // Optimised algorithm to erase an element from unordered vector.
-                *it = msQueuedUpdates.back();
-                msQueuedUpdates.pop_back();
-            }
+            // O(1) erase — unordered_set, no linear scan needed
+            msQueuedUpdates.erase(this);
+            mQueuedForUpdate = false;
         }

@@ -729,7 +720,7 @@ namespace Ogre {
     void Node::queueNeedUpdate(Node* n)
     {
         // Don't queue the node more than once
         if (!n->mQueuedForUpdate)
         {
             n->mQueuedForUpdate = true;
-            msQueuedUpdates.push_back(n);
+            msQueuedUpdates.insert(n);       // O(1) hash insert
         }
     }