CVE-2026-2603

HIGH

Keycloak: keycloak: unauthorized authentication via disabled saml identity provider

Title source: cna
STIX 2.1

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.

References (6)

Core 6
Core References
Vendor Advisory vendor-advisory x_refsource_redhat
RHSA-2026:3925
https://access.redhat.com/errata/RHSA-2026:3925
Vendor Advisory vendor-advisory x_refsource_redhat
RHSA-2026:3926
https://access.redhat.com/errata/RHSA-2026:3926
Vendor Advisory vendor-advisory x_refsource_redhat
RHSA-2026:3947
https://access.redhat.com/errata/RHSA-2026:3947
Vendor Advisory vendor-advisory x_refsource_redhat
RHSA-2026:3948
https://access.redhat.com/errata/RHSA-2026:3948
Vdb Entry, X_Refsource_Redhat vdb-entry x_refsource_redhat
https://access.redhat.com/security/cve/CVE-2026-2603
Issue Tracking, X_Refsource_Redhat issue-tracking x_refsource_redhat
RHBZ#2440300
https://bugzilla.redhat.com/show_bug.cgi?id=2440300

Scores

CVSS v3 8.1
EPSS 0.0040
EPSS Percentile 31.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact total

Details

CWE
CWE-306
Status published
Products (8)
org.keycloak/keycloak-server-spi-private 0 - 26.5.5Maven
org.keycloak/keycloak-services 0 - 26.5.5Maven
Red Hat/Red Hat build of Keycloak 26.2 26.2-16
Red Hat/Red Hat build of Keycloak 26.2 26.2.14-1
Red Hat/Red Hat build of Keycloak 26.2.14
Red Hat/Red Hat build of Keycloak 26.4 26.4-12
Red Hat/Red Hat build of Keycloak 26.4 26.4.10-1
Red Hat/Red Hat build of Keycloak 26.4.10
Published Mar 18, 2026
Tracked Since Mar 18, 2026