Vulnerability Description
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.2 before 0.10.0, the SKILL_MENTION_RE and strip_re regular expressions in backend/open_webui/utils/middleware.py parsed <$skillId|label> skill mentions with overlapping quantifiers, allowing an authenticated chat message containing <$ without a closing > to trigger quadratic backtracking and block the asyncio event loop. This issue is fixed in version 0.10.0.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Openwebui | Open Webui | >= 0.9.2, < 0.10.0 |
Related Weaknesses (CWE)
References
- https://github.com/open-webui/open-webui/commit/61a26722155ec6ee1b629cf8dfcf9750Patch
- https://github.com/open-webui/open-webui/releases/tag/v0.10.0ProductRelease Notes
- https://github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gwExploitMitigationVendor Advisory
- https://github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gwExploitMitigationVendor Advisory
FAQ
What is CVE-2026-59220?
CVE-2026-59220 is a vulnerability with a CVSS score of 6.5 (MEDIUM). Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.2 before 0.10.0, the SKILL_MENTION_RE and strip_re regular expressions in backend/open_webui/utils/middle...
How severe is CVE-2026-59220?
CVE-2026-59220 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-2026-59220?
Check the references section above for vendor advisories and patch information. Affected products include: Openwebui Open Webui.