CVE-2026-2603: Keycloak SAML broker authentication bypass via disabled Identity Provider

CVE-2026-2603 · Severity: high · CVSS 8.1 · Published 2026-03-18

A security flaw has been identified in Keycloak, a widely used identity and access management solution. An attacker can bypass security controls by sending a specially crafted login response from an external identity provider, even if that provider has been disabled by administrators. This could allow unauthorized users to gain access to protected applications and sensitive data, potentially leading to a full account takeover.

Technologies: Keycloak, org.keycloak:keycloak-server-spi-private (Maven), org.keycloak:keycloak-services (Maven). Vendors: Keycloak, Maven.

Quick answers

Is CVE-2026-2603 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-2603 being exploited in the wild.
How severe is CVE-2026-2603?
High severity, with a CVSS score of 8.1, published 18 March 2026.
Which products and versions are affected?
Keycloak < 26.5.5; Keycloak-Server-Spi-Private <= 26.5.5; Keycloak-Services <= 26.5.5; org.keycloak:keycloak-server-spi-private (Maven) < 26.5.5, <= 26.5.5, ECOSYSTEM:introduced=0,fixed=26.5.5; and 1 more.
Is there a fix for CVE-2026-2603?
Yes. org.keycloak:keycloak-server-spi-private (Maven): upgrade to 26.5.5 or later; org.keycloak:keycloak-services (Maven): upgrade to 26.5.5 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-2603 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-2603?
Check whether you run Keycloak, Keycloak-Server-Spi-Private, Keycloak-Services or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • org.keycloak:keycloak-server-spi-private (Maven): upgrade to 26.5.5 or later
    # set org.keycloak:keycloak-server-spi-private to 26.5.5 in your pom.xml or build.gradle
  • org.keycloak:keycloak-services (Maven): upgrade to 26.5.5 or later
    # set org.keycloak:keycloak-services to 26.5.5 in your pom.xml or build.gradle

Technical details

A vulnerability classified as Missing Authentication for Critical Function (CWE-306) exists in Keycloak's SAML broker component. The root cause is an improper enforcement of the 'disabled' status for Identity Providers during IdP-initiated broker logins. A remote attacker with low privileges can exploit this by sending a valid SAML response to the Keycloak SAML endpoint, successfully completing the broker login process despite the IdP being administratively disabled. This leads to unauthorized authentication and potential privilege escalation. The issue is addressed in Red Hat build of Keycloak versions 26.2.14 and 26.4.10.

Affected products

  • Red Hat build of Keycloak 26.2 Fixed in 26.2.14-1
  • Red Hat build of Keycloak 26.4 Fixed in 26.4.10-1

Identifiers

  • CVE-2026-2603
  • GHSA-x4p7-7chp-64hq

Timeline

  • 2026-03-05: patched: Red Hat released security advisories RHSA-2026:3925 and RHSA-2026:3926
  • 2026-03-18: advisory: NVD published the CVE record

References

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