Auth bypass in Open-Webui
CVE-2026-109283
Open WebUI from 0.11.1 before 0.11.4 contains an authorization bypass in the OAuth token exchange endpoint, which reads role claims only from the provider's userinfo response and keeps the user's existing role when no roles claim is found, ignoring roles sent only in the ID token. Users with a linked account whose identity provider role no longer satisfies the OAuth role policy can send a valid provider access token to POST /api/v1/auths/oauth/{provider}/token/exchange to obtain a session retaining their previous role.
Vulnerability class: Broken Access Control
Published .
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:L/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/open-webui/open-webui/security/advisories/GHSA-2rr4-q6pg-m5g3 (vendor-advisory)
- www.vulncheck.com/advisories/open-webui-0.11.1-before-0.11.4-authorization-bypa… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-109283?
- CVE-2026-109283 is a medium-severity vulnerability in Open-Webui, classified under Incorrect Authorization. CVSS score: 5.4/10. Published 2026-10-12.
- How severe is CVE-2026-109283?
- Medium severity. CVSS v3 base score is 5.4 out of 10.