RHSA-2026:6475HighCVSS 8.1

Red Hat Security Advisory: Red Hat build of Keycloak 26.2.15 Update

Published
April 2, 2026
Last Modified
August 31, 2026

🔗 CVE IDs covered (5)

CVE-2026-3872 →CVE-2026-4282 →CVE-2026-4325 →CVE-2026-4634 →CVE-2026-4636 →

📋 Description

CVE-2026-3872 — keycloak: Keycloak: Information disclosure due to redirect_uri validation bypass CVE-2026-4282 — keycloak: Keycloak: Privilege escalation via forged authorization codes due to SingleUseObjectProvider isolation flaw CVE-2026-4325 — keycloak: Keycloak: Replay of action tokens via improper handling of single-use entries CVE-2026-4634 — keycloak: Keycloak: Denial of Service via excessive processing of OpenID Connect scope parameters CVE-2026-4636 — keycloak: Keycloak: UMA policy bypass allows authenticated users to gain unauthorized access to victim-owned resources.

🎯 Affected products1

  • Red Hat build of Keycloak 26.2.15

✅ Remediation

Before applying the update, back up your existing installation, including all applications, configuration files, databases and database settings, and so on. Workaround: To mitigate this vulnerability, avoid using wildcards in `redirect_uri` configurations within Keycloak. Restricting `redirect_uri` to explicit, fully qualified URIs prevents the bypass of validation logic. This configuration change may require a service restart or reload to take effect. Workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

🔗 References (3)