CVE-2025-11419

HIGH7.5EPSS 0.10%

Keycloak TLS Client-Initiated Renegotiation Denial of Service

Published: 10/27/2025Modified: 5/5/2026

Description

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.

Affected packages (1)

CVSS scores

SourceVersionSeverityVector
osvCVSS 3.1HIGH7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References (11)