Summary
This article lists the security issues and quality improvements included in this out-of-band update.
Applies to: Windows Server 2019
This out-of-band update includes fixes and quality 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.
- [Remote Desktop Services (known issue)] Fixed: This update addresses an issue affecting Remote Desktop Services (RDS) after installing the September 2026 Windows security update (KB5122876). In affected environments, RDS might become unstable, causing RDP connection and sign-in failures or servers to become unresponsive during Remote Desktop configuration. Related tools, including Microsoft Management Console (MMC), RDS Licensing Diagnoser, File Explorer, and the Windows Update page, might also stop responding.
- [8-channel or 3D audio modes] Fixed: Some USB Audio Class 1.0 devices functioning as expected in standard stereo configurations failed when using multichannel audio features, including 8-channel or 3D audio modes. (Note: There are other audio symptoms not resolved in this OOB update. See the “Known issues in this update” section for more information.)
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
USB Audio Class 1.0 devices with error Code 10 or no output
Symptoms
After installing the September 8, 2026, Windows security update, some USB Audio Class 1.0 devices might fail to start or produce audio. Affected devices might experience one or more of the following symptoms: The device displays an error in Device Manager: "This device cannot start (Code 10).” No audio output. Volume controls are unresponsive or remain at zero. Sound settings are unresponsive or unavailable. This issue is limited to USB Audio Class 1.0 devices.
Resolution
Microsoft is working on a resolution and will update this documentation when more information is available.
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 |
|---|---|
|
This out-of-band update is available only from the Microsoft Update Catalog. |
File information
A list of the files that are included in this out-of-band 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 out-of-band update KB5129238.
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