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.
access.redhat.com/errata/RHSA-2023:7854
access.redhat.com/errata/RHSA-2023:7855
access.redhat.com/errata/RHSA-2023:7856
access.redhat.com/errata/RHSA-2023:7857
access.redhat.com/errata/RHSA-2023:7858
access.redhat.com/security/cve/CVE-2023-6563
bugzilla.redhat.com/show_bug.cgi?id=2253308
github.com/keycloak/keycloak/issues/13340