CVE-2026-2603

Keycloak: keycloak: unauthorized authentication via disabled saml identity provider

8.1 HighFix available

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 profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: None

Exploit likelihood

0.45%Up 0.3 points since Mar 18, 2026

What each source reports

CVE List Score used 8.1

Keycloak: keycloak: unauthorized authentication via disabled saml identity provider

Record: CVE-2026-2603
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weakness: CWE-306, CWE-306
Updated: 2026-11-02

EUVDEUVD-2026-12690 8.1

Record: EUVD-2026-12690
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-x4p7-7chp-64hq 8.1

Keycloak: Unauthorized authentication via disabled SAML Identity Provider

Record: GHSA-x4p7-7chp-64hq
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weakness: CWE-306
Updated: 2026-11-02

NVD 8.1

Record: CVE-2026-2603
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weakness: CWE-306
Updated: 2026-11-02

OSVGHSA-x4p7-7chp-64hq 8.1

Keycloak: Unauthorized authentication via disabled SAML Identity Provider

Record: GHSA-x4p7-7chp-64hq
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weakness: CWE-306
Updated: 2026-11-02

OSVBIT-keycloak-2026-2603 No score

Keycloak: keycloak: unauthorized authentication via disabled saml identity provider

Record: BIT-keycloak-2026-2603
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`org.keycloak:keycloak-services` Maven	before 26.5.5	26.5.5
`org.keycloak:keycloak-server-spi-private` Maven	before 26.5.5	26.5.5
`keycloak` Bitnami	26.2.0 up to 26.2.14, 26.4.0 up to 26.4.10	26.2.1426.4.10
`org.keycloak:keycloak-services` Maven	before 26.5.5, plus listed versions 1.0-alpha-11.0-alpha-1-120620131.0-alpha-21.0-alpha-31.0-alpha-4 Show 45 moreShow less 1.0-beta-11.0-beta-1-201505211.0-beta-1-201505231.0-beta-21.0-beta-31.0-beta-41.0-final1.0-rc-11.0-rc-21.0.1.Final1.0.2.Final1.0.3.Final1.0.4.Final1.0.5.Final1.1.0.Beta11.1.0.Beta21.1.0.Final1.1.1.Final1.2.0.Beta11.2.0.CR11.2.0.Final1.3.0.Final1.3.1.Final1.4.0.Final1.5.0-Final1.5.0.Final1.5.1.Final1.6.0.Final1.6.1.Final1.7.0.CR11.7.0.Final1.8.0.Alpha11.8.0.CR11.8.0.CR21.8.0.CR31.8.0.Final1.8.1.Final1.9.0.CR11.9.0.Final1.9.1.Final1.9.2.Final1.9.3.Final1.9.4.Final1.9.5.Final1.9.7.Final	26.5.5
`org.keycloak:keycloak-server-spi-private` Maven	before 26.5.5, plus listed versions 10.0.010.0.110.0.211.0.011.0.1 Show 45 moreShow less 11.0.211.0.312.0.012.0.112.0.212.0.312.0.413.0.013.0.114.0.015.0.015.0.115.0.215.1.015.1.116.0.016.1.016.1.117.0.017.0.118.0.018.0.118.0.219.0.019.0.119.0.219.0.32.4.0.CR12.4.0.Final2.5.0.CR12.5.0.Final2.5.1.Final2.5.4.Final2.5.5.Final20.0.020.0.120.0.220.0.320.0.420.0.521.0.021.0.121.0.221.1.021.1.1	26.5.5

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-2603 is a high vulnerability (CVSS 8.1) in Red Hat Build Of Keycloak 26.2, published March 18, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.45%, the 39th percentile. Fixed in org.keycloak:keycloak-services 26.5.5.

References

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Left out here: 282 versions. The JSON record has them.