Description
A flaw was found in Keycloak. This vulnerability allows an unauthenticated remote attacker to cause a denial of service (DoS) by repeatedly initiating TLS 1.2 client-initiated renegotiation requests to exhaust server CPU resources, making the service unavailable.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | keycloak | < 26.0.16, 26.2.0 – < 26.2.10, 26.4.0 – < 26.4.1 | 26.0.16 |
| Red Hat | Red Hat build of Keycloak 26.0 | — | — |
| Red Hat | Red Hat build of Keycloak 26.0.16 | — | — |
| Red Hat | Red Hat build of Keycloak 26.2 | — | — |
| Red Hat | Red Hat build of Keycloak 26.2.10 | — | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | org.keycloak:keycloak-quarkus-dist | < 26.0.16 | 26.0.16 | GHSA-q8hq-4h99-fj7x |
| Maven | org.keycloak:keycloak-quarkus-dist | >= 26.1.0, < 26.2.10 | 26.2.10 | GHSA-q8hq-4h99-fj7x |
| Maven | org.keycloak:keycloak-quarkus-dist | >= 26.3.0, < 26.4.1 | 26.4.1 | GHSA-q8hq-4h99-fj7x |
Advisories 1
- WID-SEC-2025-2224 Keycloak: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 27, 2025
References
- RHSA-2025:18254 vendor-advisory
- RHSA-2025:18255 vendor-advisory
- RHSA-2025:18889 vendor-advisory
- RHSA-2025:18890 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2025-11419 vdb-entry
- RHBZ#2402142 issue-tracking
- https://github.com/keycloak/keycloak/discussions/25209
- https://github.com/keycloak/keycloak/issues/43020