Microsoft releases patch for authentication issues in Windows Server

Microsoft has released several out-of-band updates for Windows Server. They patch a bug that prevents users from logging in to certain domain controllers. The bug was in an earlier security update for the OS.

Microsoft has released six different updates for Windows Server versions 2008, 2012, 2016 and 2019. It is an out-of-band update that the company says does not fix security vulnerabilities, but an authentication bug. This bug ensures that in some cases end users can no longer log in to a system in an Active Directory.

These are applications on which users can log in via single sign-on to applications with the Kerberos authentication protocol. The bug arose after users installed security updates released during the previous Patch Tuesday. System administrators must download the oob update from the Microsoft Update Catalog or directly from the website. The patch will not be released automatically via Windows Update.