Open WebUI: Any authenticated user can cancel another user's chat generation via the chat delete endpoint

SummaryDELETE /api/v1/chats/id cancelled a chat's in-flight tasks before it checked whether the caller was allowed to delete that chat. Any authenticated user who knew another user's chat id could therefore abort that user's running model response, title generation or tag generation. The deletion...

Open WebUI: Any authenticated user can cancel another user's chat generation via the chat delete endpoint

Summary DELETE /api/v1/chats/id cancelled a chat's in-flight tasks before it checked whether the caller was allowed to delete that chat. Any authenticated user who knew another user's chat id could therefore abort that user's running model response, title generation or tag generation. The deletio...

GHSA-3VF6-64VR-3G56 Open WebUI: Any authenticated user can cancel another user's chat generation via the chat delete endpoint

Summary DELETE /api/v1/chats/id cancelled a chat's in-flight tasks before it checked whether the caller was allowed to delete that chat. Any authenticated user who knew another user's chat id could therefore abort that user's running model response, title generation or tag generation. The deletio...

CVE-2026-70483 Open WebUI: Any authenticated user can cancel another user's chat generation via the chat delete endpoint

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.6 until 0.11.0, DELETE /api/v1/chats/id cancelled a chat's in-flight tasks before checking whether the caller could delete that chat. Any authenticated user who knew another user's chat id could abort...

CVE-2026-70483 Open WebUI: Any authenticated user can cancel another user's chat generation via the chat delete endpoint

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.6 until 0.11.0, DELETE /api/v1/chats/id cancelled a chat's in-flight tasks before checking whether the caller could delete that chat. Any authenticated user who knew another user's chat id could abort...

CVE-2026-70483

Open WebUI (self-hosted AI platform) contained an authorization bypass in the delete_chat_by_id handler (backend/open_webui/routers/chats.py) serving DELETE /api/v1/chats/{id}. The in-flight task cancellation was placed before ownership and permission checks, so any authenticated user with the de...