KB5005539 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10

The .NET Framework 3.5 and 4.8 have been updated to version KB5005539. This cumulative update for Windows 10 rolled out on October 12, 2021.

Version KB5005539 comes with reliability improvements and not much else. Here is what Microsoft has to say:

The October 12, 2021 update for Windows 10, version 2004, Windows Server, version 2004, Windows 10, version 20H2, Windows Server, version 20H2, and Windows Version 21H1 includes cumulative reliability improvements in .NET Framework 3.5 and 4.8. We recommend that you apply this update as part of your regular maintenance routines. Before you install this update, see the Prerequisites and Restart requirement sections.

The existing memory pressure algorithm used in the GC.AddMemoryPressure API is triggering induced GC too aggressively. This update provides an alternative algorithm that is less aggressive. An application can opt into the new algorithm, by setting:

COMPlus_GCNewMemoryPressure environment variable to 1

This is applicable for any application that use the GC.AddMemoryPressure API.

There was previously a preview build with the same version number (KB5005539), but this is a whole Windows Hardware Quality Labs Testing version.