Open WebUI: ReDoS in skill-mention regexes causes whole-instance DoS on default config
Summary
| CVE | CVE-2026-59220 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-09 17:17:03 UTC |
| Updated | 2026-07-10 18:15:48 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 6.5 MEDIUM from [email protected]
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.003190000 probability, percentile 0.237930000 (date 2026-07-12)
Problem Types: CWE-1333 | CWE-1333 CWE-1333: Inefficient Regular Expression Complexity
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | DECLARED | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Openwebui | Open Webui | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Open-webui | Open-webui | affected >= 0.9.2, < 0.10.0 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/open-webui/open-webui/security/advisories/GHSA-ffpj-xv5c-p3gw | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | github.com | Exploit, Mitigation, Vendor Advisory |
| github.com/open-webui/open-webui/releases/tag/v0.10.0 | [email protected] | github.com | Product, Release Notes |
| github.com/open-webui/open-webui/commit/61a26722155ec6ee1b629cf8dfcf9750... | [email protected] | github.com | Patch |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.