CVE-2026-9796: redhat build_of_keycloak

Vulnerability summary

CVE-2026-9796 is a medium (CVSS 6.5) vulnerability in redhat build_of_keycloak. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 30.5% of scored vulnerabilities.

Timeline

1. 28-05-2026
   PublishedVulnerability first disclosed.
2. 15-09-2026
   Last modifiedVulnerability information updated.

Description

A flaw was found in Keycloak. An authenticated administrator with the `manage-clients` role can exploit a Time-of-check to time-of-use (TOCTOU) vulnerability in the name-based admin role checks. This allows the attacker to escalate their privileges to `realm-admin` for all users within the realm, granting them extensive control over the system. The composite role relationship persists even after the attacker's own permissions are revoked and across system reboots.

• CWE-367Time-of-check Time-of-use (TOCTOU) Race ConditionThe product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.