CVE-2026-95503 Keycloak-services: keycloak-services: potential kdc spoofing bypass when kerberos password authentication is enabled
Attackers can spoof the KDC to bypass authentication in Keycloak when Kerberos password auth is enabled without SPNEGO, gaining unauthorized access.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-95503?
CVE-2026-95503 is a medium-severity authentication bypass vulnerability in Red Hat Build of Keycloak, published on 22 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-347
Which versions are affected by CVE-2026-95503?
How do I fix CVE-2026-95503?
No fix has been published for CVE-2026-95503 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-95503 being exploited?
There is no known exploitation of CVE-2026-95503 in the wild and no public exploit code.
Sources
Also known as GHSA-35j3-ccrv-pgvj.