Affected: Red Hat Single Sign-On 7.6 for RHEL 7, Red Hat Single Sign-On 7.6 for RHEL 8, Red Hat Single Sign-On 7.6 for RHEL 9, Red Hat RHEL-8 based Middleware Containers, Red Hat Single Sign-On 7.6.6, Red Hat Build of Keycloak

An unconstrained memory consumption vulnerability was discovered in Keycloak. It can be triggered in environments which have millions of offline tokens (> 500,000 users with each having at least 2 saved sessions). If an attacker creates two or more user sessions and then open the "consents" tab of the admin User Interface, the UI attempts to load a huge number of offline client sessions leading to excessive memory and CPU consumption which could potentially crash the entire system.