CVE-2026-97847 Keycloak-services: keycloak-services: client manager can substitute sessionless token principal via hardcoded-claim mappers to obtain realm administrator authority

Description

A flaw was found in the protocol mapper and identity resolution components of Keycloak. The issue occurs when a client manager uses hardcoded-claim mappers to override identity claims in sessionless service-account tokens. Because these tokens lack a session ID, Keycloak may incorrectly resolve the token bearer as a different, highly privileged user based on the manipulated claims. This can allow an attacker with limited client management permissions to impersonate a realm administrator and gain full control over the realm.

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

High

Privileges required

Low

Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

Low

Affected products and versions