CVE-2026-109283: Open WebUI 0.11.1 before 0.11.4 Authorization Bypass via OAuth Token Exchange
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.
Affected Software
Event History
Frequently Asked Questions
Who is exposed to this issue?
Open WebUI deployments running versions 0.11.1 through before 0.11.4 are exposed if they use OAuth role policy enforcement and have users with linked identity-provider accounts. The issue matters when a user's role has been removed or no longer meets the configured OAuth role policy.
What does an attacker need to exploit it?
The attacker needs a linked account and a valid access token from the configured identity provider. They can submit that token to the OAuth token exchange endpoint; no user interaction is required.
What access can be retained through the bypass?
If the provider userinfo response does not include role claims, Open WebUI retains the user's existing role rather than applying roles supplied only in the ID token. This can allow a user whose current identity-provider role is no longer authorized to obtain a session with their previous Open WebUI role.
How can I identify potentially affected users?
Review linked OAuth accounts whose identity-provider roles were removed or changed so they no longer satisfy the OAuth role policy. Accounts for which the provider's userinfo response omits role claims are particularly relevant, because those claims trigger retention of the existing Open WebUI role.
What is the available remediation?
Upgrade Open WebUI to version 0.11.4 or later. The affected range is 0.11.1 through versions before 0.11.4.