Keycloak SAML Broken has Authentication Bypass by Primary Weakness

A flaw was found in org.keycloak.broker.saml. When a disabled Security Assertion Markup Language (SAML) client is configured as an Identity Provider (IdP)-initiated broker landing target, it can still complete the login process and establish a Single Sign-On (SSO) session. This allows a remote attacker to gain unauthorized access to other enabled clients without re-authentication, effectively bypassing security restrictions.

A fix is available at https://github.com/keycloak/keycloak/releases/tag/26.5.5.