CVE-2026-59220 | Open WebUI is an extensible, feature-rich, and user-friendly… | CVSS 6.5 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.

Metadata

CVE ID: CVE-2026-59220
State: PUBLISHED
Assigner: GitHub_M
Reserved: 2026-07-02 21:05 UTC
Published: 2026-07-09 16:09 UTC
Last updated: 2026-07-09 18:45 UTC
Primary CWE: CWE-1333
CWE-1333: Inefficient Regular Expression Complexity
Vendor / Product: open-webui / open-webui
Sources: cve.org · NVD

Severity & Metrics

6.5 MEDIUM CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

SSVC — CISA Coordinator

Exploitation: PoC
Automatable: no
Tech. Impact: partial

Affected products (1)

Vendor	Product	Platform	Versions
open-webui	open-webui	—	>= 0.9.2, < 0.10.0

Weakness (CWE)

CWE	Source	Description
CWE-1333	cna	CWE-1333: Inefficient Regular Expression Complexity

CVSS scores (1)

Score	Severity	Version	Source	Vector
6.5	MEDIUM	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References (3)

https://github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gw https://github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gw
https://github.com/open-webui/open-webui/commit/61a26722155ec6ee1b629cf8dfcf975098c18331 https://github.com/open-webui/open-webui/commit/61a26722155ec6ee1b629cf8dfcf975098c18331
https://github.com/open-webui/open-webui/releases/tag/v0.10.0 https://github.com/open-webui/open-webui/releases/tag/v0.10.0