CVE-2026-59220
Medium
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.
SeverityMedium
CVSS6.5
Exploit probability—
ProductOpenwebui Open Webui
PublishedJul 9, 2026
First seenJul 9, 2026
Weakness typeCWE-1333CWE-1333
How to fix
Update
- openwebui open_webui0.10.0 or later
- open-webui0.10.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| openwebui open_webui | 0.9.2 ≤ v < 0.10.0 | 0.10.0 |
| open-webuiPyPI | 0.9.2 ≤ v < 0.10.0 | 0.10.0 |
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