June 9, 2026—KB5094122 (OS Build 14393.9234)
Applies To
Release Date:
6/9/2026
Version:
OS Build 14393.9234
Summary
This article lists the security issues and quality improvements included in this cumulative security update.
Applies to: Windows Server 2016
This security update includes fixes and improvements that are a part of the following update:
The following is a summary of the issues that this update addresses. The bold text within the brackets indicates the item or area of the change we are documenting.
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[Secure Boot]
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This update adds a new policy setting, LimitSecureBootRequiredServiceData, under Computer Configuration > Administrative Templates > Windows Components > Secure Boot. When this setting is enabled, Windows limits the Secure Boot service data it sends by suppressing the event normally sent to Microsoft. This policy is also included in the Windows Restricted Traffic Limited Functionality Baseline package. For information about the policy, see Manage connections from Windows 10 and Windows 11 operating system components to Microsoft services.
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With this update, Windows quality updates include additional high confidence device targeting data, increasing coverage of devices eligible to automatically receive new Secure Boot certificates. Devices receive the new certificates only after demonstrating sufficient successful update signals, maintaining a controlled and phased rollout. ​​​​​​​
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[Domain controller (known issue)] Fixed: Addressed an issue that affects DFS (Distributed File System) Namespaces on servers with hostnames that are exactly 15 characters long. ​​​​​​​
If you installed earlier updates, only the new updates contained in this package will be downloaded and installed on your device.
For more information about security vulnerabilities, please refer to the new Security Update Guide website and the June 2026 Security Updates.
For more information about Windows 10, version 1607, see its update history page.
For information about Windows update terminology, see the article about the types of Windows updates and the monthly quality update types.
Known issues in this update
Microsoft is not currently aware of any issues with this update.
Applies to: Windows 10 Enterprise LTSB 2016 and Windows 10 IoT Enterprise 2016 LTSB
This security update includes fixes and improvements that are a part of the following update:
The following is a summary of the issues that this update addresses. The bold text within the brackets indicates the item or area of the change we are documenting.
-
[Secure Boot]
-
This update adds a new policy setting, LimitSecureBootRequiredServiceData, under Computer Configuration > Administrative Templates > Windows Components > Secure Boot. When this setting is enabled, Windows limits the Secure Boot service data it sends by suppressing the event normally sent to Microsoft. This policy is also included in the Windows Restricted Traffic Limited Functionality Baseline package. For information about the policy, see Manage connections from Windows 10 and Windows 11 operating system components to Microsoft services.
-
With this update, Windows quality updates include additional high confidence device targeting data, increasing coverage of devices eligible to automatically receive new Secure Boot certificates. Devices receive the new certificates only after demonstrating sufficient successful update signals, maintaining a controlled and phased rollout.
-
If you installed earlier updates, only the new updates contained in this package will be downloaded and installed on your device.
For more information about security vulnerabilities, please refer to the new Security Update Guide website and the June 2026 Security Updates.
For more information about Windows 10, version 1607, see its update history page.
For information about Windows update terminology, see the article about the types of Windows updates and the monthly quality update types.
Known issues in this update
Microsoft is not currently aware of any issues with this update.
How to get this update
Before you install this update
To install updates released on or after January 14, 2025, we recommend you first install the latest Servicing Stack Update (SSU). If your device or offline image does not have the latest SSU installed, you might not be able to install this update.
Caution Until you install the SSU, this update might not be offered to your device. To reduce your security risk, install the SSU as soon as possible.
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If you use Windows Update, the latest SSU (KB5094141) will be offered to you automatically. If the latest SSU is not installed, you might not be able to install this update.
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If you use Windows Update for Business, the latest SSU (KB5094141) will be offered to you automatically. If the latest SSU is not installed, you might not be able to install this update.
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If you use the Update Catalog, we recommend you download and install the latest SSU (KB5094141). If the latest SSU is not installed, you might not be able to install this update.
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If you are a Windows Server Update Services (WSUS) administrator, you must approve SSU KB5094141 and this update KB5094122.
For general information about SSUs, see Servicing stack updates.
Deployment
If you deploy dynamic updates such as this update to an existing Windows image, ensure the boot.stl file is included as part of the installation media. Failure to include the file might prevent devices from successfully starting from the installation media and can result in error code 0xc0430001.
Note The boot.stl file is used during Secure Boot validation and must match the Windows version and architecture of the image you are updating.
To ensure the boot.stl file is included as part of the installation media, do one of the following:
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Use the Update WinPE script to update an existing Windows image. (Recommended)
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Manually copy the boot.stl file from the devices Windows\Boot\EFI folder to the corresponding folder on your installation media before deploying the update.
For information about how to apply Dynamic Update packages to existing Windows images, see Update Windows installation media with Dynamic Update.
Get and install this update
To get and install this update, use one of the following Windows and Microsoft release channels.
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This update will be downloaded and installed automatically from Windows Update. |
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This update will be downloaded and installed automatically from Windows Update for Business in accordance with configured policies. |
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To get the standalone package for this update, go to the Microsoft Update Catalog website. For information about how to download and install updates from the Update Catalog, see How to download updates that include drivers and hotfixes from the Windows Update Catalog. |
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This update will automatically sync with Windows Server Update Services (WSUS) if you configure Products and Classifications as follows:
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. |
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.
Related topics
Secure BootÂ
Windows Secure Boot certificate expirationÂ
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.
Microsoft Store application updates
Windows updates do not install Microsoft Store application updates. If you are an enterprise user, see Microsoft Store apps - Configuration Manager. If you are a consumer user, see Get updates for apps and games in Microsoft Store.
End of support
Windows Server 2016 and Windows 10 2016 LTSB end of support
Microsoft will no longer provide free software updates from Windows Update, technical assistance, or security fixes on the following end dates:
♦ Windows 10 Enterprise LTSB 2016: October 13, 2026
♦ Windows 10 IoT Enterprise 2016 LTSB: October 13, 2026
♦ Windows Server 2016: January 12, 2027
For more information, see Plan for Windows Server 2016 and Windows 10 2016 LTSB end of support.
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