Description
A flaw was found in Keycloak. When the configuration uses JWT tokens for authentication, the tokens are cached until expiration. If a client uses JWT tokens with an excessively long expiration time, for example, 24 or 48 hours, the cache can grow indefinitely, leading to an OutOfMemoryError. This issue could result in a denial of service condition, preventing legitimate users from accessing the system.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
keycloak
Default version status: unaffected
23.0.0 to < 26.0.11affected26.1.0 to < 26.1.5affected
Red Hat Red Hat Build of Keycloak
Default version status: unaffected
Red Hat Red Hat build of Keycloak 26.0
Default version status: affected
26.0.11-2 to < *unaffected
Red Hat Red Hat build of Keycloak 26.0
Default version status: affected
26.0-12 to < *unaffected
Red Hat Red Hat build of Keycloak 26.0
Default version status: affected
26.0-13 to < *unaffected
Red Hat Red Hat Single Sign-On 7
Default version status: affected
References
- https://access.redhat.com/errata/RHSA-2025:4335 ↗
- https://access.redhat.com/errata/RHSA-2025:4336 ↗
- https://access.redhat.com/security/cve/CVE-2025-2559 ↗
- https://bugzilla.redhat.com/show_bug.cgi?id=2353868 ↗
- https://github.com/keycloak/keycloak/commit/a10c8119d4452b866b90a9019b2cc159919276ca ↗
- https://github.com/keycloak/keycloak/issues/38576 ↗