CVE-2026-87994
Open WebUI: Channel members can overwrite another member's message via the chat completions endpoint
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N |
| NVDNVD · Analyzed | 3.1 | Medium4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.37% · top 69% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.3.
Weakness
Affected products
- affected >= 0.9.5, < 0.11.1
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPIopen-webuiGHSA-fmqh-xp37-5hr8 (opens in a new tab)
References (4)
- https://github.com/open-webui/open-webui/security/advisories/GHSA-fmqh-xp37-5hr8 (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/open-webui/open-webui/pull/28631 (opens in a new tab)x_refsource_MISC
- https://github.com/open-webui/open-webui/commit/7d392bedc9c1aaecc94509a58e59186b614433dc (opens in a new tab)x_refsource_MISC
- https://github.com/open-webui/open-webui/releases/tag/v0.11.1 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-fmqh-xp37-5hr8 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-87994)Record last updated .