CVE-2026-16102: Red Hat Build Of Keycloak

High severity, CVSS 8.1. EPSS: 0.5% chance of exploitation in the next 30 days.

A flaw was found in the Dynamic Client Registration (DCR) component of Keycloak, an identity and access management solution. The default DCR policy fails to properly validate the claim path for User Property mappers, allowing them to write values to sensitive internal claim locations. An attacker with a standard user account and a limited Initial Access Token can exploit this to forge administrative roles in their access token. This allows the attacker to take over other clients, steal confidential secrets, and potentially gain full administrative control over the realm.

Affected products

• Red Hat Build Of Keycloak: from 26.4, before 26.4.14 (fixed in 26.4.14); from 26.6, before 26.6.5 (fixed in 26.6.5)
• Red Hat Data Grid: version 8.0 only
• Red Hat JBoss Enterprise Application Platform Expansion Pack: affected versions not specified
• Red Hat Single Sign-On: version 7.0 only

Published 2026-08-05. Last modified 2026-08-31.