It was found that SAML authentication in Keycloak 3.4.3.Final incorrectly authenticated expired certificates. A malicious user could use this to access unauthorized data or possibly conduct further attacks.
keycloak before version 4.0.0.final is vulnerable to a infinite loop in session replacement. A Keycloak cluster with multiple nodes could mishandle an expired session replacement and lead to an infinite loop. A malicious authenticated user could use this flaw to achieve Denial of Service on the server.