Auth bypass in Red Hat Build Of Keycloak

CVE-2026-93999

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 class: Broken Access Control

CVSS v3 metric

CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-93999?
CVE-2026-93999 is a medium-severity vulnerability in Red Hat Build Of Keycloak, classified under Missing Authorization. CVSS score: 4.2/10. Published 2026-09-19.
How severe is CVE-2026-93999?
Medium severity. CVSS v3 base score is 4.2 out of 10.