CVE-2026-2603: Red Hat Build Of Keycloak

High severity, CVSS 8.1. EPSS: 0.7% chance of exploitation in the next 30 days.

A flaw was found in Keycloak. A remote attacker could bypass security controls by sending a valid SAML response from an external Identity Provider (IdP) to the Keycloak SAML endpoint for IdP-initiated broker logins. This allows the attacker to complete broker logins even when the SAML Identity Provider is disabled, leading to unauthorized authentication.

Affected products

• Red Hat Build Of Keycloak: from 26.2, before 26.2.14 (fixed in 26.2.14); from 26.4, before 26.4.10 (fixed in 26.4.10)

Published 2026-03-18. Last modified 2026-08-18.