Auth bypass in Red Hat Build Of Keycloak
CVE-2026-18218
A flaw was found in the TokenManager component of the Keycloak identity management service. When an administrator attempts to revoke tokens for a specific application (client) using a "not-before" policy, the revocation may be silently ignored if the overall security realm already has an older, non-zero revocation policy in place. This issue can allow previously issued tokens to remain valid for refreshing sessions and accessing user information even after an administrator has attempted to invalidate them. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Vulnerability class: Broken Access Control
EPSS: 0.001 (3.1th percentile) — read the EPSS interpretation.
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
- secalert@redhat.com (x_refsource_REDHAT, vdb-entry, Vendor Advisory)
- RHBZ#2508313 (x_refsource_REDHAT, issue-tracking, Issue Tracking, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-18218?
- CVE-2026-18218 is a medium-severity vulnerability in Red Hat Build Of Keycloak, classified under Missing Authorization. CVSS score: 4.2/10. Published 2026-07-31.
- How severe is CVE-2026-18218?
- Medium severity. CVSS v3 base score is 4.2 out of 10.