CVE-2026-18967: Red Hat Build Of Keycloak

High severity, CVSS 8.1. EPSS: 0.2% chance of exploitation in the next 30 days.

A flaw was found in the SAML broker component of Keycloak, an identity and access management solution. When configured as a SAML broker using the IdP-Initiated flow, Keycloak fails to enforce the OneTimeUse condition in SAML assertions. This allows an attacker who captures a valid, unused assertion to replay it multiple times. Successful exploitation could allow an attacker to hijack a user's session and gain unauthorized access to the system as that user.

Affected products

• Red Hat Build Of Keycloak: affected versions not specified
• Red Hat JBoss Enterprise Application Platform Expansion Pack: affected versions not specified

Published 2026-08-06. Last modified 2026-08-10.