GHSA-w9f8-gxf9-rhvw: Open WebUI's Insecure Direct Object Reference (IDOR) allows access to other users' memories

Open WebUI has an insecure direct object reference (IDOR, a flaw where an app doesn't properly check if a user should access specific data) in its retrieval API that lets any authenticated user read other users' private memories and uploaded files by guessing collection names like 'user-memory-{USER_UUID}' or 'file-{FILE_UUID}'. The vulnerability exists because the API checks that a user is logged in, but doesn't verify they own the data they're requesting.