Auth bypass in Red Hat Build Of Keycloak 26.2
CVE-2026-2603
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.
Vulnerability class: Broken Authentication
EPSS: 0.004 (33.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.
Affected products
- Red Hat Build Of Keycloak 26.2 — versions 26.2.14-1, 26.2-16
- Red Hat Build Of Keycloak 26.2.14
- Red Hat Build Of Keycloak 26.4 — versions 26.4.10-1, 26.4-12
- Red Hat Build Of Keycloak 26.4.10
Weakness classification (CWE)
References
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vdb-entry)
- secalert@redhat.com (x_refsource_REDHAT, issue-tracking)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-2603?
- CVE-2026-2603 is a high-severity vulnerability in Red Hat Build Of Keycloak 26.2, classified under Missing Authentication for Critical Function. CVSS score: 8.1/10. Published 2026-03-18.
- How severe is CVE-2026-2603?
- High severity. CVSS v3 base score is 8.1 out of 10.