Microsoft Support:
The January 29, 2026 update for Windows 11, version 25H2 includes security and cumulative reliability improvements in .NET Framework 3.5 and 4.8.1. 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.
Summary
Security ImprovementsThere are no new security improvements in this release. This update is cumulative and contains all previously released security improvements.
Quality and Reliability Improvements
| .NET Runtime | - Addresses an issue to add verification logic for ClickOnce to support SHA384 and SHA512. - Addresses an issue in cases where the arm64 CLR could crash when code generates and catches a NullReferenceException within the same function. |
Known issues in this update
Microsoft is not currently aware of any issues in this update.How to get this update
Install this update| Release Channel | Available | Next Step |
|---|---|---|
| Windows Update and Microsoft Update | Yes | Go to Settings > Update & Security > Windows Update. In the Optional updates available area, you’ll find the link to download and install the update. |
| Windows Update for Business | Yes | Go to Settings > Update & Security > Windows Update. In the Optional updates available area, you’ll find the link to download and install the update. |
| Microsoft Update Catalog | Yes | To get the standalone package for this update, go to the Microsoft Update Catalog website. |
| Windows Server Update Services (WSUS) | No | You can import this update into WSUS manually. See the Microsoft Update Catalog for instructions. |
File information
For a list of the files that are provided in this update, download the file information for cumulative update.
Prerequisites
To apply this update, you must have .NET Framework 3.5 or 4.8.1 installed.Restart requirement
You must restart the computer after you apply this update if any affected files are being used. We recommend that you exit all .NET Framework-based applications before you apply this update. Source:
