fix: re-verify ownership on custom-logger payload branch for id lookups

litellm/proxy/spend_tracking/spend_management_endpoints.py

@@ -2896,6 +2896,12 @@ async def ui_view_request_response_for_request_id(
             end_time_utc=end_date_obj,
         )
         if payload is not None:
+            if not caller_is_admin and prisma_client is not None:
+                await _assert_user_can_view_request_id(
+                    prisma_client=prisma_client,
+                    user_api_key_dict=user_api_key_dict,
+                    request_id=request_id,
+                )
             return payload
 
     # Fallback: the list endpoint omits the heavy columns for performance, so

tests/test_litellm/proxy/spend_tracking/test_spend_management_endpoints.py

@@ -2566,6 +2566,53 @@ async def test_ui_view_request_response_rejects_foreign_row_inserted_after_owner
         app.dependency_overrides.pop(ps.user_api_key_auth, None)
 
 
+@pytest.mark.asyncio
+async def test_ui_view_request_response_custom_logger_rechecks_after_fetch(client, monkeypatch):
+    """The custom-logger payload branch re-verifies ownership after fetching. A row
+    that appears between the pre-check and the payload read (so the pre-check saw only
+    owned rows) is caught on the post-fetch check, so the foreign payload is not served."""
+    owner_states = iter(
+        [
+            [{"user": "user_1", "team_id": None}],
+            [{"user": "user_1", "team_id": None}, {"user": "victim_user", "team_id": None}],
+        ]
+    )
+
+    class MockDB:
+        async def query_raw(self, sql_query, *params):
+            if 'SELECT DISTINCT "user", team_id' in sql_query:
+                return next(owner_states)
+            return []
+
+    class MockPrisma:
+        def __init__(self):
+            self.db = MockDB()
+
+    class LeakyLogger:
+        async def get_request_response_payload(self, request_id, start_time_utc, end_time_utc):
+            return {"messages": [{"role": "user", "content": "victim prompt"}], "response": {"id": "r"}}
+
+    monkeypatch.setattr("litellm.proxy.proxy_server.prisma_client", MockPrisma())
+    monkeypatch.setattr(
+        litellm.logging_callback_manager,
+        "get_active_additional_logging_utils_from_custom_logger",
+        lambda: [LeakyLogger()],
+    )
+    app.dependency_overrides[ps.user_api_key_auth] = lambda: UserAPIKeyAuth(
+        user_role=LitellmUserRoles.INTERNAL_USER, user_id="user_1"
+    )
+    try:
+        response = client.get(
+            "/spend/logs/ui/shared-id",
+            params={"start_date": "2026-01-01 00:00:00"},
+            headers={"Authorization": "Bearer sk-test"},
+        )
+        assert response.status_code == 403
+        assert "victim prompt" not in response.text
+    finally:
+        app.dependency_overrides.pop(ps.user_api_key_auth, None)
+
+
 @pytest.mark.asyncio
 async def test_ui_view_spend_logs_request_id_owner_scoped_by_id_only(
     client, monkeypatch