KB5126056: Setup Dynamic Update for Windows 11, versions 24H2 and 25H2: September 8, 2026

Applies To

Windows 11 version 24H2, all editions Windows 11 version 25H2, all editions

Summary

This update addresses security vulnerabilities in Windows setup binaries or any files that setup uses for feature updates in Windows 11, version 24H2 and Windows 11, version 25H2.

How to get this update

Install this update

To install this update, use one of the following release channels.

Available	Next step
	This update is available through Windows Update. It will be downloaded and installed automatically.

Available	Next step
	To get the standalone package for this update, go to the Microsoft Update Catalog website. To download updates from the Update Catalog, see Steps to download updates from the Windows Update Catalog.

Available	Next step
	This update will automatically sync with Windows Server Update Services (WSUS) if you configure Products and Classifications as follows: Product: Windows 11 Classification: Update To set up your WSUS server to sync based on products and classifications, see Synchronizing Update by Product and Classification. To manually import updates into WSUS, see Import updates into WSUS by using PowerShell.

Available

Next step

This update will automatically sync with Windows Server Update Services (WSUS) if you configure Products and Classifications as follows:

Product: Windows 11
Classification: Update

To set up your WSUS server to sync based on products and classifications, see Synchronizing Update by Product and Classification.

To manually import updates into WSUS, see Import updates into WSUS by using PowerShell.

About this update

Item	Description
Prerequisites	There are no prerequisites to apply this update.
Restart information	You might not have to restart your computer after you apply this update.
Update replacement information	This update replaces the previously released update KB5106084
File information	A list of the files that are included in this update are provided in a CSV (Comma delimited) (.csv) file. The file can be opened in a text editor such as Notepad or in Microsoft Excel. Note:* The English (United States) version of this software update might contain files for additional languages. Download the file information for update 5126056.

References

Description of the standard terminology that is used to describe Microsoft software updates

Query words: Setup DU