Medium [CVE-2026-12388] Privilege escalation to realm administrator via improper authorization in identity provider mapper

A flaw was found in the Identity Provider (IdP) mapper component of Keycloak, which is used to manage how user information from external services is mapped to Keycloak users.

An administrator with limited permissions to manage identity providers can exploit this flaw by creating a "Hardcoded Role" mapper that assigns high-level administrative roles (like realm-admin) to themselves or others. This allows a restricted administrator to bypass security checks and gain full control over the entire realm.

The Red Hat Product Security team has assessed the severity of this vulnerability as Moderate, given that it requires the attacker to already possess high-level administrative privileges (manage-identity-providers). Successful exploitation allows an attacker to escalate their privileges to realm-admin, granting them full control over the Keycloak realm.

The vulnerability's root cause is a failure to enforce proper authorization checks (specifically requireMapRole) within the Identity Provider mapper endpoint. Weakness: CWE-266.

Affected Red Hat products: Red Hat Build of Keycloak. Red Hat does not currently list a fixing RHSA for this CVE.