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.
References8
- access.redhat.com/errata/RHSA-2025:18254
- access.redhat.com/errata/RHSA-2025:18255
- access.redhat.com/errata/RHSA-2025:18889
- access.redhat.com/errata/RHSA-2025:18890
- access.redhat.com/security/cve/CVE-2025-11419
- bugzilla.redhat.com/show_bug.cgi?id=2402142
- github.com/keycloak/keycloak/discussions/25209
- github.com/keycloak/keycloak/issues/43020
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 1% percentile: 54 · as of 11 November 2026
- CWE
- CWE-770
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.