medium4.9
CVE-2025-2559
Keycloak Denial of Service (DoS) Vulnerability via JWT Token Cache
Impact
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 packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| maven | org.keycloak:keycloak-services | <= 26.1.4 | none recorded |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- 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
- https://github.com/advisories/GHSA-2935-2wfm-hhpv
- https://nvd.nist.gov/vuln/detail/CVE-2025-2559