What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 6.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-22 · updated 2026-09-22
• Weakness: CWE-347

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.

Affected products

• Red Hat build of Keycloak 26.4: all versions
• Red Hat Single Sign-On 7: all versions

References

• https://access.redhat.com/security/cve/CVE-2026-95503
• https://bugzilla.redhat.com/show_bug.cgi?id=2537744

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