.NET Framework July 2021 Security and Quality Rollup

Tara Overfield

Yesterday, we released the July 2021 Security and Quality Rollup Updates for .NET Framework.


The June Security and Quality Rollup Update does not contain any new security fixes. See February 2021 Security and Quality Rollup for the latest security updates.

Quality and Reliability

This release contains the following quality and reliability improvements.

  • Addresses a regression introduced in previous updates. We now honor WinTrust policy setting “Ignore timestamp revocation checks” setting when validating timestamps in ClickOnce manifests.
  • When the process is not under high memory pressure it tends to favor doing BGCs over doing full compacting GCs. This is usually desirable but if the app behavior changes dramatically, it could cause much of the fragmentation in older generations (ie, gen2 and LOH) to be unused. You can collect GC ETW events which tell you how much fragmentation there is in gen2 and LOH and verify if you are in this situation.
Windows Forms
  • Addresses an issue in Property Grid control to prevent incorrect data read in some scenarios in 64 bit processes.
  • Addresses an issue where System.Drawing double frees allocated memory when failing to get printer settings.
  • Addresses an issue affecting a DataGrid contained in an outer ScrollViewer.
  • Addresses a crash due to ElementNotAvailableException in a ListView with custom data-item automation peers.

1 Common Language Runtime (CLR)2 Windows Presentation Foundation (WPF)

Getting the Update

The Security and Quality Rollup is available via Windows Update, Windows Server Update Services, and Microsoft Update Catalog.

Microsoft Update Catalog

You can get the update via the Microsoft Update Catalog. For Windows 10, NET Framework 4.8 updates are available via Windows Update, Windows Server Update Services, Microsoft Update Catalog. Updates for other versions of .NET Framework are part of the Windows 10 Monthly Cumulative Update.

**Note**: Customers that rely on Windows Update and Windows Server Update Services will automatically receive the .NET Framework version-specific updates. Advanced system administrators can also take use of the below direct Microsoft Update Catalog download links to .NET Framework-specific updates. Before applying these updates, please ensure that you carefully review the .NET Framework version applicability, to ensure that you only install updates on systems where they apply.

The following table is for Windows 10 and Windows Server 2016+ versions.

Product VersionCumulative Update
Windows 10 21H1
.NET Framework 3.5, 4.8Catalog5003537
Windows 10, version 20H2 and Windows Server, version 20H2
.NET Framework 3.5, 4.8Catalog5003537
Windows 10 2004 and Windows Server, version 2004
.NET Framework 3.5, 4.8Catalog5003537
Windows 10 1909
.NET Framework 3.5, 4.8Catalog5003539
Windows 10 1809 (October 2018 Update) and Windows Server 20195004228
.NET Framework 3.5, 4.7.2Catalog5003541
.NET Framework 3.5, 4.8Catalog5003538
Windows 10 1607 (Anniversary Update) and Windows Server 2016
.NET Framework 3.5, 4.6.2, 4.7, 4.7.1, 4.7.2Catalog5004238
.NET Framework 4.8Catalog5004115

The following table is for earlier Windows and Windows Server versions.

Product VersionSecurity and Quality Rollup
Windows 8.1, Windows RT 8.1 and Windows Server 2012 R25004231
.NET Framework 3.5Catalog4578953
.NET Framework 4.5.2Catalog4578956
.NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2Catalog5004122
.NET Framework 4.8Catalog5004118
Windows Server 20125004230
.NET Framework 3.5Catalog4578950
.NET Framework 4.5.2Catalog4578954
.NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2Catalog5004121
.NET Framework 4.8Catalog5004117
Windows 7 SP1 and Windows Server 2008 R2 SP15004229
.NET Framework 3.5.1Catalog4578952
.NET Framework 4.5.2Catalog4578955
.NET Framework 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2Catalog5004120
.NET Framework 4.8Catalog5004116
Windows Server 20085004232
.NET Framework 2.0, 3.0Catalog4578951
.NET Framework 4.5.2Catalog4578955
.NET Framework 4.6, 4.6.2Catalog5004120


Previous Monthly Rollups

The last few .NET Framework Monthly updates are listed below for your convenience: