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.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
None
No disruption
CVSS Vector v3.1
Weakness Type (CWE)
References 6
https://access.redhat.com/errata/RHSA-2026:3925
secalert@redhat.com
https://access.redhat.com/errata/RHSA-2026:3926
secalert@redhat.com
https://access.redhat.com/errata/RHSA-2026:3947
secalert@redhat.com
https://access.redhat.com/errata/RHSA-2026:3948
secalert@redhat.com
https://access.redhat.com/security/cve/CVE-2026-2603
secalert@redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2440300
secalert@redhat.com