Note
- 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.
Summary
This article lists the fixes and quality improvements included in this out-of-band update.
Applies to: Windows Server 2019
This out-of-band update includes fixes and improvements that are part of the following update:
The following is a summary of the issues that this out-of-band update addresses when you install this update. The bold text within the brackets indicates the item or area of the change we are documenting.
- [Domain controllers (known issue)] Fixed: After installing the April 14, 2026, (KB5082123) Windows security update and restarting, domain controllers with multi-domain forests that use Privileged Access Management (PAM), might experience startup issues. In some cases, Local Security Authority Subsystem Service (LSASS) might stop responding, leading to repeated restarts, and preventing authentication and directory services, which can make the domain unavailable.
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 April 2026 Security Updates.
For information about Windows update terminology, see the article about the types of Windows updates and the monthly quality update types. For an overview of Windows 10, version 1809, see its update history page.
Known issues in this update
Remote Desktop security warnings might not display correctly
Symptoms
After installing this update, the security warning that appears when opening Remote Desktop (RDP) files might not display correctly in some cases.
This issue might occur when you use more than one monitor with different display scaling settings (for example, one display set to 100% and another set to 125%). When this happens, the warning window might show overlapping text or partially hidden buttons, which can make the message difficult to read or interact with.
Resolution
This issue is resolved in Windows updates released on and after May 12, 2026 (such as KB5087538). We recommend you install the latest Windows update for your device as it contains important improvements and issue resolutions, including this one.
Servicing stack update (KB5082118) - 17763.8642
Microsoft now combines the latest servicing stack update (SSU) for your operating system with the latest cumulative update (LCU). SSUs improves the reliability of the update process and includes fixes to the servicing stack, the component that installs Windows updates.
Note: This servicing stack update (SSU) includes enhanced logic to verify whether a device is hosted on Azure, leveraging an updated certificate chain for validation. To ensure that the device can access the required certificate update domains to successfully download and install certificate updates, see Certificate downloads and revocation lists and Azure Certificate Authority details. To learn more about SSUs, see Servicing stack updates.
How to get this update
Before you install this update
You must have installed the August 10, 2021, SSU (KB5005112) before installing this out-of-band update.
Install this update
To install this update, use one of the following Microsoft release channels.
| Available | Next Step |
|---|---|
|
This out-of-band update is available only from the Update Catalog. |
If you want to remove this update
Note
- CAUTION Before you decide to remove this update, please see Understanding the risks: Why you should not uninstall security updates.
- 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
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.
Download the file information for this out-of-band update KB5091573.
Download the file information for SSU (KB5082118) - version 17763.8642.
Related information
Notice for Microsoft Store application updates
Note
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 information
Note
- Windows Server 2019 and Windows 10 Enterprise LTSC 2019 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 LTSC 2019: January 9, 2029
- ♦ Windows Server 2019: January 9, 2029
- We recommend that you upgrade to a later version of Windows Server.
Change log
| Change date | Change description |
|---|---|
| May 12, 2026 |
|
| April 23, 2026 |
|