Vulnerability · Published Mar 18, 2026 · Assigned by redhat

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

High 8.1

In plain English

A high-severity missing authentication in Red Hat build of Keycloak 26.2 from Red Hat. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 39% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.1High
Exploit odds (30 days)0.5%top 60.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official 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 packages & fixed versions

EcosystemPackageFixed inAdvisory
Mavenorg.keycloak:keycloak-server-spi-private26.5.5GHSA-x4p7-7chp-64hq
Mavenorg.keycloak:keycloak-services26.5.5GHSA-x4p7-7chp-64hq

Affected products (as reported)

Weakness: CWE-306 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

References