6.8 Medium

CVE-2026-95503 Keycloak-services: keycloak-services: potential kdc spoofing bypass when kerberos password authentication is enabled

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.

CVSS 3.1 detail

CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Exploitable from the adjacent network, without an account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector: Adjacent network
Attack complexity: High
Privileges required: None
Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

Affected products and versions

Product	Affected versions	Fixed in
Red Hat Build of Keycloak	Versions not published
Red Hat Single Sign-On 7	Versions not published
Red Hat build of Keycloak 26.6.8	Versions not published

References

RHSA-2026:95761 access.redhat.com
access.redhat.com access.redhat.com
RHBZ#2537744 bugzilla.redhat.com

Timeline

Published September 22, 2026
Last modified November 6, 2026

The 276 CVEs of Red Hat Build of Keycloak →

CVE-2026-9797 Keycloak: keycloak: privilege escalation via client authentication manipulation by an authenticated administrator 6.5 Medium CVE-2026-97848 Keycloak-services: keycloak-services: protocol mapper with jsontype=json bypasses token sanitization 6.5 Medium CVE-2026-97367 Keycloak-services: keycloak-services: dcr azp and sid claim substitution allows account rest session takeover 6.4 Medium CVE-2026-96547 Keycloak-services: keycloak-services: dcr registration-time claim-path gap allows forging realm_access.roles 6.5 Medium

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