CVE-2026-59220
Open WebUI: ReDoS in skill-mention regexes causes whole-instance DoS on default config
CVSS Score
6.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-1333 |
| Vendor | open-webui |
| Product | open-webui |
| Published | Jul 9, 2026 |
| Last Updated | Jul 9, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
open-webui / open-webui
>= 0.9.2, < 0.10.0