Time-of-check Time-of-use (TOCTOU) Race Condition in Red Hat build of Keycloak - CVE-2026-9796
Published: September 11, 2026
Vulnerability identifier: #VU148994
CSH Severity: Low
CVSS v4: 8.5 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-9796
CWE-ID: CWE-367
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to escalate privileges to realm-admin for all users within the realm.
The vulnerability exists due to a time-of-check to time-of-use race condition in name-based admin role checks when processing administrative role checks. A remote privileged user can exploit the race condition to escalate privileges to realm-admin for all users within the realm.
Exploitation requires the manage-clients role. The resulting composite role relationship persists after the user\'s permissions are revoked and across system reboots.
Affected software
Red Hat build of Keycloak
How to mitigate CVE-2026-9796
Install security update from vendor's website.
Red Hat build of Keycloak - update to 26.6.6