The SAML broker consumer endpoint in Keycloak before version 4.6.0.Final ignores expiration conditions on SAML assertions. An attacker can exploit this vulnerability to perform a replay attack.
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.