Auth bypass in Open-Webui
CVE-2026-59225
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.8.12 before 0.10.0, an authenticated non-admin user with read access to an arena wrapper model can reach a restricted underlying model through task endpoints such as /api/v1/tasks/moa/completions. The normal chat route resolves arena models before the final chat dispatch and therefore re-checks the selected underlying model. The task routes call utils.chat.generate_chat_completion() directly. In that direct path, arena fallback resolution happens after the wrapper access check and then recurses with bypass_filter=True, skipping the selected submodel's access check. This issue is fixed in version 0.10.0.
Vulnerability class: Broken Access Control
EPSS: 0.002 (11.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L.
Affected products
- Open-webui — versions >= 0.8.12, < 0.10.0
- Openwebui Open_webui
Weakness classification (CWE)
References
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_CONFIRM, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-59225?
- CVE-2026-59225 is a medium-severity vulnerability in Open-Webui, classified under Missing Authorization. CVSS score: 5.4/10. Published 2026-07-09.
- How severe is CVE-2026-59225?
- Medium severity. CVSS v3 base score is 5.4 out of 10.