CVE-2026-59220
MEDIUMOpen WebUI: ReDoS in skill-mention regexes causes whole-instance DoS on default config
Title source: cnaDescription
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.
References (3)
Core 3
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gw
X_Refsource_Misc x_refsource_misc
https://github.com/open-webui/open-webui/commit/61a26722155ec6ee1b629cf8dfcf975098c18331
X_Refsource_Misc x_refsource_misc
https://github.com/open-webui/open-webui/releases/tag/v0.10.0
Scores
CVSS v3
6.5
EPSS
0.0037
EPSS Percentile
30.0%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
no
Technical Impact
partial
Details
CWE
CWE-1333
Status
published
Products (3)
open-webui/open-webui
>= 0.9.2, < 0.10.0
openwebui/open_webui
0.9.2 - 0.10.0
pypi/open-webui
0.9.2 - 0.10.0PyPI
Published
Jul 09, 2026
Tracked Since
Jul 09, 2026