GHSA-q8hq-4h99-fj7x
Keycloak TLS Client-Initiated Renegotiation Denial of Service
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Maven | org.keycloak:keycloak-quarkus-dist | < 26.0.16 | 26.0.16 |
| Maven | org.keycloak:keycloak-quarkus-dist | >= 26.1.0, < 26.2.10 | 26.2.10 |
| Maven | org.keycloak:keycloak-quarkus-dist | >= 26.3.0, < 26.4.1 | 26.4.1 |
Details
As written in the advisory (Markdown source, shown as plain text).
Keycloak is vulnerable to a Denial of Service (DoS) attack due to the default JDK setting that permits Client-Initiated Renegotiation in TLS 1.2. An unauthenticated remote attacker can repeatedly initiate TLS renegotiation requests to exhaust server CPU resources, making the service unavailable. Immediate mitigation is available by setting the `-Djdk.tls.rejectClientInitiatedRenegotiation=true` Java system property in the Keycloak startup configuration.
References
External links from the advisory. They lead to third-party sites.
- https://github.com/keycloak/keycloak/security/advisories/GHSA-q8hq-4h99-fj7x
- https://nvd.nist.gov/vuln/detail/CVE-2025-11419
- https://github.com/keycloak/keycloak/issues/43020
- https://access.redhat.com/errata/RHSA-2025:18254
- https://access.redhat.com/errata/RHSA-2025:18255
- https://access.redhat.com/errata/RHSA-2025:18889
- https://access.redhat.com/errata/RHSA-2025:18890
- https://access.redhat.com/security/cve/CVE-2025-11419
- https://bugzilla.redhat.com/show_bug.cgi?id=2402142
- https://github.com/keycloak/keycloak
- https://github.com/keycloak/keycloak/discussions/25209