CVE-2026-59220: open-webui
Vulnerability summary
CVE-2026-59220 is a medium (CVSS 6.5) vulnerability in open-webui. EPSS estimates a 0.57% chance of exploitation in the next 30 days, higher than 46.5% of scored vulnerabilities. 1 public exploit is recorded.
Timeline
- 09-07-2026PublishedVulnerability first disclosed.
- 09-07-2026Last modifiedVulnerability information updated.
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 metrics
3 scores · 3 sources · 1 version- OSV · PypiEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- NVDNIST6.5MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.57%
Chance of exploitation in the next 30 days
Percentile
47%
Versus all other CVEs
30-day change
0.00 pp
From 0.57% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundOpen Webui
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Open-webui1 product
- open-webui≥ 0.9.2, < 0.10.0
Openwebui1 product
- open_webui≥ 0.9.2, < 0.10.0
PyPI1 product
- open-webui≥ 0.9.2, < 0.10.0
3 vendors · 3 products
References
7 links- github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gwX Refsource CONFIRMWEBExploitMitigationVendor Advisory
- github.com/open-webui/open-webui/commit/61a26722155ec6ee1b629cf8dfcf975098c18331X Refsource MISCWEBPatch
- pypi.org/project/open-webuiPACKAGE