CVE-2026-88000: Openwebui Open Webui

Medium severity, CVSS 6.5. EPSS: 0.6% chance of exploitation in the next 30 days.

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.10.0 until 0.11.1, DELETE /api/v1/chats/{id}/messages/{message_id} used the chat-history deletion helper in backend/open_webui/models/chats.py to follow childrenIds without recording visited message identifiers. An authenticated user could store a cyclic chat tree and delete a message, causing a synchronous infinite loop on the server request loop that blocked every user's requests until the process was killed. This issue is fixed in version 0.11.1.

Affected products

• Openwebui Open Webui: from 0.10.0, before 0.11.1 (fixed in 0.11.1)

Published 2026-09-09. Last modified 2026-09-14.