CVE-2026-87994
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.
Scoring
- Severity
- MEDIUM
- CVSS base score
- 4.3
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
- CWE
- CWE-639, CWE-862
- Published
- 2026-09-09
- Last modified
- 2026-09-09
Affected products
- open-webui open-webui
Weakness type
Related vulnerabilities
- CVE-2026-84062 — BurgerEditor 3.0.0 through 3.4.0 contains an issue with authorization bypass through...
- CVE-2026-87997 — Open WebUI: Any authenticated user can inject chats into another user's folder via chat completions
- CVE-2026-47156 — MantisBT: SOAP API Authentication Bypass with Privilege Escalation to Administrator
- CVE-2026-67403 — Cash Collect contains an improper authorization vulnerability in the Sage AR Automation API....
- CVE-2026-86763 — snipe-it 7.0.12 through 8.6.3 Authorization Bypass via Importer
- CVE-2026-86761 — snipe-it 8.6.3 before 8.7.0 Authorization Bypass via print endpoints
- CVE-2026-86743 — Snipe-IT before 8.7.0 Authorization Bypass via Asset Acceptance Report
- CVE-2026-87809 — Siyuan before v3.8.2 Information Disclosure via Export Preview