CVE-2026-87994Open WebUI: Channel members can overwrite another member's message via the chat completions endpoint
- 4.3MediumCVSS base score
- 0.37%Exploitation in 30 daysEPSS · top 68% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
- https://github.com/open-webui/open-webui/security/advisories/GHSA-fmqh-xp37-5hr8 (opens in a new tab)x_refsource_CONFIRMexploit
Timeline
ID reserved
By GitHub_M
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
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 68% of all CVEs (13 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.
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
References4
- 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)
- EUVD EUVD-2026-75178 (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://cveledger.app/cve/CVE-2026-87994)Record last updated .