| Component | Open WebUI |
| Severity | medium (CVSS 6.5) |
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| Published (NVD) | 2026-08-04 |
| Last modified | 2026-09-18 |
| Affected versions | open_webui >= 0.9.6, < 0.11.0 |
| Fixed in | 0.11.0 |
| Weakness | CWE-1333 |
| CISA KEV | not listed |
NVD 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.
What to do
- Upgrade Open WebUI to
0.11.0or later. - Do not expose the component's API or UI to the internet without authentication in front of it.
Sources
- NVD: CVE-2026-70493
- https://github.com/open-webui/open-webui/pull/27471
- https://github.com/open-webui/open-webui/security/advisories/GHSA-2f54-p244-32q6
- https://github.com/open-webui/open-webui/commit/3ab2026262ef6f09810e4d235c5f9a9cb903e595
- https://github.com/open-webui/open-webui/releases/tag/v0.11.0
Read more
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