: Denies any authentication attempt that cannot be "strongly mapped" (e.g., via a Security Identifier (SID) ). Deadlines :
Requires the certificate to be bound specifically to an Active Directory account via the SID extension or by using explicit mapping methods recommended by Microsoft. strongcertificatebindingenforcement location
Understanding and Locating StrongCertificateBindingEnforcement: Securing Windows Certificate Authentication in 2026 : Denies any authentication attempt that cannot be
To identify certificates that do not meet the new criteria, monitor the on domain controllers for the following Event IDs: Microsoft Learn +1 Registry Location The key is
. Microsoft Learn +1 Registry Location The key is located on all Domain Controllers at the following path: Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Kdc Name: StrongCertificateBindingEnforcement Type: REG_DWORD PKI Solutions +3 Configuration Values By default, this key may not exist; if absent, the system uses the default behavior dictated by the most recently installed Windows Updates. You can manually create it to force a specific mode: Microsoft Learn +1 Value Mode Description 0 Disabled No enforcement; no audit events are logged. 1 Compatibility Allows authentication if the certificate can be weakly mapped to a user, but logs warning events (39, 40, 41). 2 Full Enforcement Only allows authentication if the certificate is strongly mapped (e.g., contains a SID) or has an explicit mapping. Timeline and Deadlines Microsoft has implemented this change in phases to allow organizations to reissue certificates: 11 sites KB5014754 Certificate based authentication changes on DC's Jan 28, 2025 —