8.1
HIGH CVSS 3.1
CVE-2026-2603
Keycloak: keycloak: unauthorized authentication via disabled saml identity provider
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.

INFO

Published Date :

March 18, 2026, 2:16 a.m.

Last Modified :

March 18, 2026, 2:16 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-2603 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH 53f830b8-0a3f-465b-8143-3b8a9948e749
CVSS 3.1 HIGH [email protected]
Solution
Update Keycloak to address unauthorized authentication via SAML IdP-initiated broker logins.
  • Update Keycloak to a patched version.
  • Review SAML IdP configurations.
  • Disable broker logins if not needed.
  • Monitor authentication logs.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-2603 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-2603 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-2603 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Mar. 18, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
    Added CWE CWE-306
    Added Reference https://access.redhat.com/errata/RHSA-2026:3925
    Added Reference https://access.redhat.com/errata/RHSA-2026:3926
    Added Reference https://access.redhat.com/errata/RHSA-2026:3947
    Added Reference https://access.redhat.com/errata/RHSA-2026:3948
    Added Reference https://access.redhat.com/security/cve/CVE-2026-2603
    Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2440300
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.