Summary
This article lists the security issues and quality improvements included in this cumulative security update.
Applies to: Windows Server 2019
This security update includes fixes and quality improvements that are part of the following update:
The following is a summary of the issues that this update addresses when you install this update. The bold text within the brackets indicates the item or area of the change we are documenting.
[Secure Boot] This update includes additional high confidence device targeting data, increasing coverage of devices eligible to automatically receive new Secure Boot certificates. Certificate deployment via Windows updates continues across supported PCs and non-managed business devices in the coming months.
[Date and Time] This update adjusts Morocco Standard Time to reflect Morocco's transition to permanent UTC+00:00 effective September 20, 2026. This change ensures that the correct local time is displayed after the transition.
[Windows Code Integrity policies] Improves application compatibility during Windows certificate-authority rotation by recognizing Microsoft Windows Production PCA 2026 RSA2048-SHA256 as equivalent to PCA 2011.
[Remote Desktop] This update addresses an issue that affects Remote Desktop audio redirection. Audio from the remote session might not play on the local computer in certain configurations.
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, see the Security Update Guide and September 2026 Security Updates.
For information about Windows update terminology, see types of Windows updates and monthly quality update types. For an overview of Windows 10, version 1809, see its update history page.
Known issues in this update
We are currently not aware of any issues with this update.
Servicing stack update (KB5122875) - 17763.9242
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.
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 cumulative update.
Get and install this update
To get and install this update, use one of the following Windows or Microsoft release channels.
| Available | Next Step |
|---|---|
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This update will be downloaded and installed automatically from Windows Update. |
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 cumulative update KB5122876).
Download the file information for SSU (KB5122875) - version 17763.9242.
Related topics
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.Windows Secure Boot certificate expiration
Important: Secure Boot certificates used by most Windows devices have started expiring in June 2026. This might affect the ability of certain personal and business devices to boot securely if not updated in time. To avoid disruption, we recommend reviewing the guidance and taking action to update certificates in advance. For details and preparation steps, see Windows Secure Boot certificate expiration and CA updates.End of support
Microsoft will no longer provide free software updates from Windows Update, technical assistance, or security fixes on the following end dates. We recommend that you upgrade to a later version of Windows Server.
- Windows 10 Enterprise LTSC 2019: January 9, 2029
- Windows Server 2019: January 9, 2029