Microsoft Releases Windows 11 KB5126056 and KB5124015 Dynamic Updates

Microsoft has released new Windows 11 Dynamic Updates alongside the September 2026 Windows 11 Patch Tuesday updates, covering versions 23H2, 24H2, 25H2, and 26H1.

As Neowin reports, the latest batch includes both Setup Dynamic Updates and Safe OS Dynamic Updates. Windows Update downloads and installs them automatically.

What the new Dynamic Updates change

Safe OS Dynamic Updates improve the Windows Recovery Environment, or WinRE, while Setup Dynamic Updates refresh Windows Setup binaries and files used during feature updates.

For Windows 11 26H1, Microsoft released KB5126041 as the Setup Dynamic Update to address security vulnerabilities in Windows Setup files. KB5124011 updates WinRE to version 10.0.28000.2949.

Windows 11 24H2 and 25H2 receive KB5126056, which addresses security vulnerabilities affecting Setup binaries and feature-update files. The corresponding KB5124015 Safe OS Dynamic Update brings WinRE to version 10.0.26100.9444.

Windows 11 23H2 also gets a pair of updates. KB5126030 refreshes Windows Setup components and addresses security vulnerabilities, while KB5122888 improves WinRE and updates it to version 10.0.22621.7581.

Windows Update handles installation automatically

Users generally don’t need to install these packages manually. Windows Update automatically downloads and applies both Setup and Safe OS Dynamic Updates during supported update processes.

The September Windows updates haven’t arrived without problems, though. Users have reported USB audio failures as well as problems accessing shared folders in Linux VMs.