{"cve":"CVE-2026-59220","nvd":{"published":"2026-07-09T17:17:03.040","modified":"2026-07-10T18:15:48.287","status":"Analyzed","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_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":6.5},"cwes":["CWE-1333"],"references":["https://github.com/open-webui/open-webui/commit/61a26722155ec6ee1b629cf8dfcf975098c18331","https://github.com/open-webui/open-webui/releases/tag/v0.10.0","https://github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gw","https://github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gw"],"products":["openwebui:open_webui"],"source":"nvd","synced_at":"2026-10-19T22:44:02.134301115+00:00"},"epss":{"cve":"CVE-2026-59220","score":0.00573,"percentile":0.47356,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-ffpj-xv5c-p3gw","url":"https://osv.dev/vulnerability/GHSA-ffpj-xv5c-p3gw","summary":"Open WebUI: ReDoS in skill-mention regexes causes whole-instance DoS on default config","modified":"2026-08-04T14:41:01.473313729Z","packages":[{"ecosystem":"PyPI","name":"open-webui","purl":"pkg:pypi/open-webui","ranges":[">=0.9.2 <0.10.0"],"fixed":["0.10.0"]}]},{"id":"PYSEC-2026-3596","url":"https://osv.dev/vulnerability/PYSEC-2026-3596","summary":"Open WebUI: ReDoS in skill-mention regexes causes whole-instance DoS on default config","modified":"2026-08-04T14:30:28.720082476Z","packages":[{"ecosystem":"PyPI","name":"open-webui","purl":"pkg:pypi/open-webui","ranges":[">=0.9.2 <0.10.0"],"fixed":["0.10.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}