diff --git a/backend/open_webui/models/models.py b/backend/open_webui/models/models.py
index ff72dcfc65..d50f722494 100755
--- a/backend/open_webui/models/models.py
+++ b/backend/open_webui/models/models.py
@@ -303,26 +303,26 @@ class ModelsTable:
             ]
 
     async def get_models_by_user_id(
-        self, user_id: str, permission: str = 'write', db: AsyncSession | None = None
+        self,
+        user_id: str,
+        permission: str = 'write',
+        db: AsyncSession | None = None,
+        user_group_ids: set[str] | None = None,
     ) -> list[ModelUserResponse]:
         models = await self.get_models(db=db)
-        user_groups = await Groups.get_groups_by_member_id(user_id, db=db)
-        user_group_ids = {group.id for group in user_groups}
+        if user_group_ids is None:
+            user_group_ids = {group.id for group in await Groups.get_groups_by_member_id(user_id, db=db)}
 
-        result = []
-        for model in models:
-            if model.user_id == user_id:
-                result.append(model)
-            elif await AccessGrants.has_access(
-                user_id=user_id,
-                resource_type='model',
-                resource_id=model.id,
-                permission=permission,
-                user_group_ids=user_group_ids,
-                db=db,
-            ):
-                result.append(model)
-        return result
+        # One grants query for all non-owned models instead of one per model
+        accessible_ids = await AccessGrants.get_accessible_resource_ids(
+            user_id=user_id,
+            resource_type='model',
+            resource_ids=[model.id for model in models if model.user_id != user_id],
+            permission=permission,
+            user_group_ids=user_group_ids,
+            db=db,
+        )
+        return [model for model in models if model.user_id == user_id or model.id in accessible_ids]
 
     def _has_permission(self, db, query, filter: dict, permission: str = 'read'):
         return AccessGrants.has_permission_filter(
diff --git a/backend/open_webui/utils/access_control/files.py b/backend/open_webui/utils/access_control/files.py
index ddb6acb066..4d6880cdfa 100644
--- a/backend/open_webui/utils/access_control/files.py
+++ b/backend/open_webui/utils/access_control/files.py
@@ -18,6 +18,7 @@ async def has_access_to_file(
     access_type: str,
     user: UserModel,
     db: AsyncSession | None = None,
+    user_group_ids: set[str] | None = None,
 ) -> bool:
     """
     Check if a user has the specified access to a file through any of:
@@ -43,7 +44,8 @@ async def has_access_to_file(
     # the object's OWNER owns that file; otherwise a read-only file laundered into an object
     # the user controls would gain write/delete on it (CWE-863). Read access is unaffected.
     knowledge_bases = await Knowledges.get_knowledges_by_file_id(file_id, db=db)
-    user_group_ids = {group.id for group in await Groups.get_groups_by_member_id(user.id, db=db)}
+    if user_group_ids is None:
+        user_group_ids = {group.id for group in await Groups.get_groups_by_member_id(user.id, db=db)}
     for knowledge_base in knowledge_bases:
         if (
             knowledge_base.user_id == user.id
@@ -60,12 +62,25 @@ async def has_access_to_file(
 
     knowledge_base_id = file.meta.get('collection_name') if file.meta else None
     if knowledge_base_id:
-        knowledge_bases = await Knowledges.get_knowledge_bases_by_user_id(user.id, access_type, db=db)
-        for knowledge_base in knowledge_bases:
-            if knowledge_base.id == knowledge_base_id and (
-                access_type == 'read' or knowledge_base.user_id == file.user_id
-            ):
-                return True
+        # Fetch the one referenced knowledge base instead of listing every
+        # knowledge base the user can access just to scan for this id.
+        knowledge_base = await Knowledges.get_knowledge_by_id(knowledge_base_id, db=db)
+        if (
+            knowledge_base
+            and (access_type == 'read' or knowledge_base.user_id == file.user_id)
+            and (
+                knowledge_base.user_id == user.id
+                or await AccessGrants.has_access(
+                    user_id=user.id,
+                    resource_type='knowledge',
+                    resource_id=knowledge_base.id,
+                    permission=access_type,
+                    user_group_ids=user_group_ids,
+                    db=db,
+                )
+            )
+        ):
+            return True
 
     # Check if the file is associated with any channels the user has access to
     channels = await Channels.get_channels_by_file_id_and_user_id(file_id, user.id, db=db)
@@ -88,7 +103,9 @@ async def has_access_to_file(
 
     # Check if the file is directly attached to a shared workspace model (per the ownership
     # note above, model write is conferred only for files the model owner owns).
-    for model in await Models.get_models_by_user_id(user.id, permission=access_type, db=db):
+    for model in await Models.get_models_by_user_id(
+        user.id, permission=access_type, db=db, user_group_ids=user_group_ids
+    ):
         knowledge_items = getattr(model.meta, 'knowledge', None) or []
         for item in knowledge_items:
             if isinstance(item, dict) and item.get('type') == 'file' and item.get('id') == file.id:
@@ -113,6 +130,9 @@ async def get_accessible_folder_files(
     if user.role == 'admin':
         return list(entries)
 
+    # One group-membership fetch for the whole folder listing
+    user_group_ids = {group.id for group in await Groups.get_groups_by_member_id(user.id, db=db)}
+
     accessible: list[dict] = []
     for entry in entries:
         if not isinstance(entry, dict):
@@ -123,7 +143,7 @@ async def get_accessible_folder_files(
             accessible.append(entry)
             continue
         if entry_type == 'file':
-            if await has_access_to_file(entry_id, 'read', user, db=db):
+            if await has_access_to_file(entry_id, 'read', user, db=db, user_group_ids=user_group_ids):
                 accessible.append(entry)
         elif entry_type == 'collection':
             if await Knowledges.check_access_by_user_id(entry_id, user.id, 'read', db=db):