Windows 10 KB5055612 fixes GPU issues in WSL and improves security

A late prototype of the Windows 10 stock wallpaper found in a leaked Windows 11 build

It is time for this month's optional non-security updates for Windows 11 and 10. Windows 10 is the first to receive April's C-update under KB5055612 (build number 19045.5796), which, slightly confusingly, contains security improvements to the Windows Kernel Vulnerable Driver Blocklist and a single fix for GPU paravirtualization support in Windows Subsystem for Linux 2.

For reference, this update was released in the Insider Program (Release Preview) last week.

Here is the changelog:

Improvements

[Graphics] Fix: The check for GPU paravirtualization was case-sensitive in Windows Subsystem for Linux 2 (WSL2). This issue might potentially cause GPU paravirtualization support to fail.

[OS Security] Updates to the Windows Kernel Vulnerable Driver Blocklist (DriverSiPolicy.p7b). Additions have been made to blocklist drivers with security vulnerabilities that have been used in Bring Your Own Vulnerable Driver (BYOVD) attacks.

Known issues in KB5055612 remain the same as before (minus the bug with a Windows Update error, which is now fully fixed). One affects systems with certain versions of Citrix software, and one is about the Windows Event Viewer displaying a SgrmBroker.exe error (Microsoft says you can safely ignore it).

You can download KB5055612 from Windows Update or the Microsoft Update Catalog. Keep in mind that today's release is optional, so feel free to skip it if you do not need or want anything from its changelog. Changes in KB5055612 will be included in the following mandatory Patch Tuesday updates.