CVE-2026-70493

Medium

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.

SeverityMedium
CVSS6.5
Exploit probability—
ProductOpenwebui Open Webui
PublishedAug 4, 2026
First seenAug 4, 2026
Weakness typeCWE-1333CWE-1333

How to fix

Update
  • openwebui open_webui0.11.0 or later
  • open-webui0.11.0 or later

Affected products

ProductAffected versionsFixed in
openwebui open_webui0.9.6 ≤ v < 0.11.00.11.0
open-webuiPyPI0.9.6 ≤ v < 0.11.00.11.0

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