CVE-2026-95503

Keycloak-services: keycloak-services: potential kdc spoofing bypass when kerberos password authentication is enabled

Published Sep 22, 2026 CVSS 3.1 · 6.8 Medium EPSS < 1% KEV · Not listed
Description
A flaw was found in the Kerberos federation provider of Keycloak, an open-source identity and access management solution. When Kerberos password authentication is used without SPNEGO, the system fails to verify the identity of the Key Distribution Center (KDC) by requesting a server ticket. This allows an attacker on the same network to spoof the KDC and bypass the authentication process, potentially gaining unauthorized access to user accounts.

Remediation

Vendor Workaround

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:/a:redhat:build_keycloak: cpe:/a:redhat:build_keycloak:26.6::el9
References
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Redhat build Of Keycloak
Redhat single Sign-on
Vendors & Products Redhat build Of Keycloak
Redhat single Sign-on
Type Values Removed Values Added
Description A flaw was found in the Kerberos federation provider of Keycloak, an open-source identity and access management solution. When Kerberos password authentication is used without SPNEGO, the system fails to verify the identity of the Key Distribution Center (KDC) by requesting a server ticket. This allows an attacker on the same network to spoof the KDC and bypass the authentication process, potentially gaining unauthorized access to user accounts.
Title Keycloak-services: keycloak-services: potential kdc spoofing bypass when kerberos password authentication is enabled
First Time appeared Redhat
Redhat build Keycloak
Redhat red Hat Single Sign On
Weaknesses CWE-347
CPEs cpe:/a:redhat:build_keycloak:
cpe:/a:redhat:red_hat_single_sign_on:7
Vendors & Products Redhat
Redhat build Keycloak
Redhat red Hat Single Sign On
References
Metrics cvssV3_1

{'score': 6.8, 'vector': 'CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Nov 6, 2026, 10:27 AM
Reserved
Sep 22, 2026, 6:42 AM
Status
Awaiting Analysis
Published
Sep 22, 2026, 8:16 AM
Modified
Nov 6, 2026, 11:17 AM
Severity
Moderate
Public date
Sep 22, 2026, 7:23 AM