{"id":"CVE-2026-70493","published":"2026-08-04T21:16:38.327","lastModified":"2026-08-05T15:17:12.060","description":"Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.6 until 0.11.0, the built-in knowledge search path in backend/open_webui/tools/knowledge_fs.py and backend/open_webui/tools/builtin.py let a chat participant choose a pattern used to grep knowledge files. Patterns containing regex metacharacters were compiled with Python's backtracking re engine and run against every line of every reachable file with no time limit, so a crafted pattern such as (x|x)*y and one matching uploaded file line can pin one CPU core and block the event loop. This causes availability impact for every other user of the affected worker. This issue is fixed in 0.11.0.","cvssScore":6.5,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwes":["CWE-1333"],"vendors":[],"products":[],"references":[{"url":"https://github.com/open-webui/open-webui/commit/3ab2026262ef6f09810e4d235c5f9a9cb903e595","tags":[]},{"url":"https://github.com/open-webui/open-webui/pull/27471","tags":[]},{"url":"https://github.com/open-webui/open-webui/releases/tag/v0.11.0","tags":[]},{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-2f54-p244-32q6","tags":[]},{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-2f54-p244-32q6","tags":[]}],"exploitRefs":[{"url":"https://github.com/open-webui/open-webui/commit/3ab2026262ef6f09810e4d235c5f9a9cb903e595","tags":[]},{"url":"https://github.com/open-webui/open-webui/pull/27471","tags":[]},{"url":"https://github.com/open-webui/open-webui/releases/tag/v0.11.0","tags":[]},{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-2f54-p244-32q6","tags":[]},{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-2f54-p244-32q6","tags":[]}],"hasPoc":true,"ai":{"summary":"The vulnerability allows a chat participant to craft a regex pattern that can consume significant CPU resources, potentially blocking the event loop and affecting other users.","exploitability":"Exploitation requires crafting a specific regex pattern; preconditions include access to the chat interface and timing of the attack.","blast_radius":"If exploited, it could impact availability for all users sharing the affected worker instance.","remediation":"Update to version 0.11.0 or later which addresses this issue.","tags":["regex","cpu-throttle","availability","patch-available"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-08-11T07:06:20.729Z"}}