A few days ago, Microsoft started rolling out the Cumulative May Update, which is now available for all supported versions of the Windows operating system. It turned out that this update brings not only bug fixes, but also problems, which are expressed in the interruption of the functioning of some platform services. The software giant has recognized the problem and will likely release a patch soon to fix the bugs.
According to available data, the packages are KB5013943 for Windows 11 (build 22000.675) and KB5013942 for Windows 10 (builds 19043.1706, 19042.1706 and 19041.1706). Installing the cumulative update may cause client and server operating system authentication failures on a number of services including Network Policy Server, Routing and Remote Access Service, Extensible Authentication Protocol, and Protected Extensible Authentication Protocol. According to the source, the problem is related to how the domain controller handles the mapping of certificates to user machine accounts. The issue affects non-domain controlled client and server OS versions.
Microsoft is currently working on a patch to fix the bugs mentioned. When exactly it will be available to users is still unknown. We recommend that users who encounter problems after installing the cumulative update manually map certificates to accounts in Active Directory.