CVE-2026-16443: Red Hat Build Of Keycloak

Critical severity, CVSS 9.1. EPSS: 0.3% chance of exploitation in the next 30 days.

A flaw was found in the SAML metadata import functionality of the keycloak-services component, which is the core engine for identity brokering in Red Hat Build of Keycloak. When importing identity provider metadata that lacks specific usage attributes for keys, the system incorrectly disables signature validation for SAML responses even if a signing certificate is provided. This issue allows an unauthenticated attacker to forge a SAML response and gain unauthorized access to a user account by knowing their external identifier.

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)

Published 2026-08-05. Last modified 2026-08-10.