What’s Vulnerable › Vulnerabilities

CVE-2026-2603: Keycloak: keycloak: unauthorized authentication via disabled saml identity provider

• Severity: high (CVSS 8.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-03-18 · updated 2026-08-18
• Weakness: CWE-306

Description

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 26.4: from 26.2 before 26.2.14; from 26.4 before 26.4.10 — fixed in 26.2.14, 26.4.10

How to fix

Upgrade to a fixed version: Red Hat build of Keycloak 26.4 26.2.14, 26.4.10. Check the vendor advisory for mitigations.

References

• https://access.redhat.com/errata/RHSA-2026:3925
• https://access.redhat.com/errata/RHSA-2026:3926
• https://access.redhat.com/errata/RHSA-2026:3947
• https://access.redhat.com/errata/RHSA-2026:3948
• https://access.redhat.com/security/cve/CVE-2026-2603
• https://bugzilla.redhat.com/show_bug.cgi?id=2440300
• https://access.redhat.com/errata/RHSA-2026:3925
• https://access.redhat.com/errata/RHSA-2026:3926
• https://access.redhat.com/errata/RHSA-2026:3947
• https://access.redhat.com/errata/RHSA-2026:3948
• https://access.redhat.com/security/cve/CVE-2026-2603
• https://bugzilla.redhat.com/show_bug.cgi?id=2440300

Get alerted when CVE-2026-2603 or the next vulnerability affects your stack