.NET Framework September 2023 Cumulative Update Preview

Salini Agarwal

Today, we are releasing the September 2023 Cumulative Update Preview for .NET Framework.

Quality and Reliability

This release contains the following quality and reliability improvements.

  • Addresses an issue with “System.ArgumentException: Illegal characters in path” in some ASP.Net MVC requests.
  • Addresses an issue with SQL event source telemetry.

Getting the Update

The Cumulative Update Preview is available via Windows Update and Microsoft Update Catalog.

Customers using Windows 11, version 22H2, you will now find .NET Framework updates on the Settings > Windows Update > Advanced options > Optional updates page.

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+ versions.

Product Version Cumulative Update
Windows 11, version 22H2
.NET Framework 3.5, 4.8.1 Catalog 5030651
Windows 11, version 21H2 5031042
.NET Framework 3.5, 4.8 Catalog 5030842
.NET Framework 3.5, 4.8.1 Catalog 5030650
Windows 10, version 22H2 5031041
.NET Framework 3.5, 4.8 Catalog 5030841
.NET Framework 3.5, 4.8.1 Catalog 5030649


Previous Monthly Rollups

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


Discussion is closed. Login to edit/delete existing comments.

  • Midnight 0

    I’m curious, is anything still relying on 3.5? Looking forward for the obsoletion plan. Make another friend for the Internet Explorer.

  • Dhanraj D 0

    Hi Salini Agarwal,

    Could you let us know when this same page will be up for “.NET Framework October 2023 Security and Quality Rollup Updates” ?


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