CVE-2026-87994
mediumOpen WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform.
Vendor / product: Openwebui — open webui
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.5 until 0.11.1, the channel branch of chat_completion in backend/open_webui/main.py checked channel write access and channel membership for a supplied message_id but did not verify that the calling user authored the targeted message. A channel member could use the chat completions endpoint to replace another member's message while preserving the victim as the stored author, altering the conversation record without gaining access to other channels. This issue is fixed in version 0.11.1.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N Affected products
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
References
- https://github.com/open-webui/open-webui/commit/7d392bedc9c1aaecc94509a58e59186b614433dc security-advisories@github.com
- https://github.com/open-webui/open-webui/pull/28631 security-advisories@github.com
- https://github.com/open-webui/open-webui/releases/tag/v0.11.1 security-advisories@github.com
- https://github.com/open-webui/open-webui/security/advisories/GHSA-fmqh-xp37-5hr8 security-advisories@github.com
- https://github.com/open-webui/open-webui/security/advisories/GHSA-fmqh-xp37-5hr8 134c704f-9b21-4f2e-91b3-4a467353bcc0