{"id":"CVE-2026-59220","state":"PUBLISHED","title":"Open WebUI: ReDoS in skill-mention regexes causes whole-instance DoS on default config","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.","publishedAt":"2026-07-09T16:09:41.127Z","updatedAt":"2026-07-09T18:45:06.768Z","severity":{"score":6.5,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["open-webui open-webui"],"affected":[{"vendor":"open-webui","product":"open-webui","versions":[{"version":">= 0.9.2, < 0.10.0","status":"affected"}]}],"references":["https://github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gw","https://github.com/open-webui/open-webui/commit/61a26722155ec6ee1b629cf8dfcf975098c18331","https://github.com/open-webui/open-webui/releases/tag/v0.10.0"],"weaknesses":["CWE-1333"],"ingestedAt":"2026-10-29T20:12:32.778Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/59xxx/CVE-2026-59220.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-59220","state":"PUBLISHED","datePublished":"2026-07-09T16:09:41.127Z","dateUpdated":"2026-07-09T18:45:06.768Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-07-02T21:05:02.925Z"},"containers":{"cna":{"title":"Open WebUI: ReDoS in skill-mention regexes causes whole-instance DoS on default config","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"open-webui","product":"open-webui","versions":[{"version":">= 0.9.2, < 0.10.0","status":"affected"}]}],"references":[{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gw","name":"https://github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gw","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/open-webui/open-webui/commit/61a26722155ec6ee1b629cf8dfcf975098c18331","name":"https://github.com/open-webui/open-webui/commit/61a26722155ec6ee1b629cf8dfcf975098c18331","tags":["x_refsource_MISC"]},{"url":"https://github.com/open-webui/open-webui/releases/tag/v0.10.0","name":"https://github.com/open-webui/open-webui/releases/tag/v0.10.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-1333","lang":"en","description":"CWE-1333: Inefficient Regular Expression Complexity","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-09T16:09:41.127Z"},"source":{"advisory":"GHSA-ffpj-xv5c-p3gw","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gw","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-09T18:44:56.824119Z","id":"CVE-2026-59220","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-09T18:45:06.768Z"}}]}}}