CVE-2026-88000 MEDIUM

CVE-2026-88000: Open WebUI: Any authenticated user can hang the server via message deletion in a cyclic chat tree

Vendor Open-Webui
Product open-webui
Weakness CWE-835
Published September 9, 2026
Last update September 10, 2026
View on NVD All CVEs

CVSS base score

6.5/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

September 9, 2026 CVE published
September 10, 2026 Record updated