A flaw was found in Keycloak. A highly privileged user with manage-clients permission can exploit this vulnerability by injecting a hardcoded role mapper into any client. This action allows the user to bypass existing scope restrictions and inject the realm-admin role into generated tokens, resulting in privilege escalation and full administrative access to the realm.
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.