Vulnerability Description
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, Open WebUI allows admins to restrict which API endpoints an API key can access. When an API key is restricted from /api/v1/messages, requests using the Authorization: Bearer sk-... header are correctly blocked with 403. However, the same key sent via the x-api-key header bypasses the restriction entirely — the request is authenticated, the model is invoked, and a full response is returned. This vulnerability is fixed in 0.9.0.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Openwebui | Open Webui | < 0.9.0 |
Related Weaknesses (CWE)
References
- https://github.com/open-webui/open-webui/security/advisories/GHSA-57q6-fvp4-pqmmExploitVendor Advisory
- https://github.com/open-webui/open-webui/security/advisories/GHSA-57q6-fvp4-pqmmExploitVendor Advisory
FAQ
What is CVE-2026-45339?
CVE-2026-45339 is a vulnerability with a CVSS score of 6.5 (MEDIUM). Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, Open WebUI allows admins to restrict which API endpoints an API key can access. When ...
How severe is CVE-2026-45339?
CVE-2026-45339 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-45339?
Check the references section above for vendor advisories and patch information. Affected products include: Openwebui Open Webui.