CVE-2026-18207 Keycloak-services: keycloak-services: client policy source-group condition bypass via duplicate group name matching

Description

A flaw was found in the client policy enforcement mechanism of Keycloak. The issue occurs when the system checks group membership by name instead of a unique identifier. An attacker with client management privileges could bypass security policies by joining a group with a matching name in a different part of the group hierarchy, potentially allowing them to register or update clients without following required security hardening profiles.

Exploitable remotely over the network, with an ordinary account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector

Network

Attack complexity

Low

Privileges required

Low

Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Affected products and versions