Keycloak OIDC Token Refresh Bypass for Disabled Clients
CVE-2026-93999 Published on September 19, 2026
Keycloak-services: keycloak-services: token refresh continues issuing tokens for disabled audience clients
A flaw was found in the OIDC protocol implementation of Keycloak, an open-source identity and access management solution. The issue occurs during the token refresh process when the server restores requested audiences from stored client IDs. Keycloak fails to verify if the target audience client is still enabled before issuing a new access token. This allows an application with an existing refresh token to continue obtaining valid access tokens for a disabled client, potentially bypassing administrative access controls for resource servers that rely on offline JWT validation.
Vulnerability Analysis
CVE-2026-93999 can be exploited with network access, and requires small amount of user privileges. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality and integrity, and no impact on availability.
Timeline
Reported to Red Hat.
Made public.
Weakness Type
What is an AuthZ Vulnerability?
The software does not perform an authorization check when an actor attempts to access a resource or perform an action.
CVE-2026-93999 has been classified to as an AuthZ vulnerability or weakness.
Products Associated with CVE-2026-93999
stack.watch emails you whenever new vulnerabilities are published in Red Hat Build Keycloak or Red Hat Single Sign On. Just hit a watch button to start following.
