September 14, 2026—KB5129237 (OS Build 20348.5631) Out-of-band

Applies To
Windows Server 2022

Announcements and messages

This section provides key notifications related to this release, including announcements, change logs, and end-of-support notices.

Windows Secure Boot certificate expiration

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.

Summary

This out-of-band update for Windows Server 2022 (KB5129237) is cumulative. It 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.

  • [Remote Desktop Services (known issue)] Fixed: This update addresses an issue affecting Remote Desktop Services (RDS) after installing the September 2026 Windows security update (KB5122882). 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, your device downloads and installs only the new updates contained in this package.

To view the latest updates about this release, visit the Windows release health dashboard or the update history page for Windows Server 2022.

Windows Server 2022 servicing stack update (KB5122881) - 20348.5614

This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. Servicing stack updates (SSU) ensure that you have a robust and reliable servicing stack so that your devices can receive and install Microsoft updates. To learn more about SSUs, see Simplifying on-premises deployment of servicing stack updates.

Known issues in this update

Windows Server Update Services (WSUS) does not display error details

After installing KB5070884 or later updates, Windows Server Update Services (WSUS) does not display synchronization error details within its error reporting. This functionality is temporarily removed to address the Remote Code Execution Vulnerability, CVE-2025-59287.

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.

How to get this update

Install this update

To install this update, use one of the following Windows and Microsoft release channels.


Available Next Step
Not available This update is only available from the Microsoft Update Catalog.

File Information

For a list of the files provided in this update, download the file information for out-of-band update 5129237.

For a list of the files provided in the servicing stack update, download the file information for the SSU (KB5122881) - version 20348.5614.