CVE-2026-59220
Open WebUI: ReDoS in skill-mention regexes causes whole-instance DoS on default config
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.
INFO
Published Date :
July 9, 2026, 5:17 p.m.
Last Modified :
July 10, 2026, 6:15 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Open WebUI to version 0.10.0.
- Apply the latest security patches.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-59220.
| URL | Resource |
|---|---|
| https://github.com/open-webui/open-webui/commit/61a26722155ec6ee1b629cf8dfcf975098c18331 | Patch |
| https://github.com/open-webui/open-webui/releases/tag/v0.10.0 | Product Release Notes |
| https://github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gw | Exploit Mitigation Vendor Advisory |
| https://github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gw | Exploit Mitigation Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-59220 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-59220
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-59220 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-59220 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jul. 10, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:* versions from (including) 0.9.2 up to (excluding) 0.10.0 Added Reference Type GitHub, Inc.: https://github.com/open-webui/open-webui/commit/61a26722155ec6ee1b629cf8dfcf975098c18331 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/open-webui/open-webui/releases/tag/v0.10.0 Types: Product, Release Notes Added Reference Type GitHub, Inc.: https://github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gw Types: Exploit, Mitigation, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gw Types: Exploit, Mitigation, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 09, 2026
Action Type Old Value New Value Added Reference https://github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gw Added SSVC {'id': 'CVE-2026-59220', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-09T18:44:56.824119Z'} -
New CVE Received by [email protected]
Jul. 09, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'open-webui', 'product': 'open-webui', 'versions': [{'status': 'affected', 'version': '>= 0.9.2, < 0.10.0'}]}] Added 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-1333 Added Reference https://github.com/open-webui/open-webui/commit/61a26722155ec6ee1b629cf8dfcf975098c18331 Added Reference https://github.com/open-webui/open-webui/releases/tag/v0.10.0 Added Reference https://github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gw