KB5066359—Security Update for Windows PowerShell (Hotpatch)
Applies To
Release Date:
9/9/2025
Version:
OS Build 20348.4166
Windows Secure Boot certificate expiration
Important: Secure Boot certificates used by most Windows devices are set to expire starting in June 2026. Microsoft has been updating these certificates on consumer and non-managed business devices for the past months. Devices that haven’t received the newer certificates will continue to start and operate normally, and standard Windows updates will continue to install. We will continue to install the newer certificates via Windows updates in the coming months.
You can check your PC status on the Windows Security app. If you are an IT administrator, follow the guidance on the Secure Boot Playbook for Windows clients and Windows Server.​​​​​​​
To learn more about Windows update terminology, see types of Windows updates and monthly quality update types. For an overview, see the update history page for Windows Server 2022.
Stay informed! Follow @WindowsUpdate for the latest updates from the Windows Release Health Dashboard.
Improvements and fixes
This security update includes quality improvements. The following summary outlines key issues addressed by this update.
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[Fix for PSDirect connections failing in Hotpatch devices] Addresses an issue in the September 2025 Windows Hotpatch update and the September 2025 Windows security update. This update includes security improvement, between host operating systems and guest virtual machine. It resolves a vulnerability that could allow unauthorized, non-administrator access during a brief window. It also improves reliability when older sessions shut down unexpectedly. Â
Note:Â If the guest virtual machine installs the September 2025 Hotpatch update, Microsoft recommends applying this update.Â
If you've already installed previous updates, your device will download and install only the new updates included in this package.
Known issue in this update
Microsoft is not currently aware of any issues with this update.
How to get this update
Before you install this update
Microsoft combines the latest servicing stack update (SSU) for your operating system with the latest cumulative update (LCU). For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.Â
Install this update
To install this update, use one of the following Windows and Microsoft release channels.
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Available |
Next Step |
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This update downloads and installs automatically from Windows Update and Microsoft Update. |
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Available |
Next Step |
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See the Windows Update option. |
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Available |
Next Step |
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See the Windows Update option. |
If you want to remove the LCU
To remove the LCU after installing the combined SSU and LCU package, use the DISM/Remove-Package command line option with the LCU package name as the argument. You can find the package name by using this command: DISM /online /get-packages.
Running Windows Update Standalone Installer (wusa.exe) with the /uninstall switch on the combined package will not work because the combined package contains the SSU. You cannot remove the SSU from the system after installation.
File information
The English (United States) version of this software update installs files that have the following attributes. This update might contain files for additional languages.
|
File name |
File version |
Date |
Time |
File size |
|
Microsoft.PowerShell.ConsoleHost.Resources.dll |
6.1.7600.16385 |
23-Aug-25 |
5:40 |
40,960 |
|
Microsoft.PowerShell.ConsoleHost.Resources.dll |
10.0.20348.4163 |
23-Aug-25 |
5:40 |
35,328 |
|
Microsoft.PowerShell.ConsoleHost.dll |
6.1.7600.16385 |
23-Aug-25 |
5:40 |
200,704 |
|
Microsoft.PowerShell.ConsoleHost.dll |
10.0.20348.4163 |
23-Aug-25 |
5:40 |
238,080 |
|
System.Management.Automation.dll |
6.1.7600.16385 |
23-Aug-25 |
5:40 |
3,010,560 |
|
System.Management.Automation.dll |
10.0.20348.4163 |
23-Aug-25 |
5:40 |
6,493,696 |
|
System.Management.Automation.Resources.dll |
6.1.7600.16385 |
23-Aug-25 |
5:40 |
253,952 |
|
System.Management.Automation.Resources.dll |
10.0.20348.4163 |
23-Aug-25 |
5:40 |
475,136 |
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