Applies To
Windows Server 2022

Release Date:

1/17/2026

Version:

OS Build 20348.4650

Change date

Change description

January 21, 2026

  • Added the known issue "Apps might become unresponsive when saving files to cloud-based storage"

​​​​Summary

This out-of-band update for Windows Server 2022 (KB5077800) is cumulative. It includes updates from previous security, along with an additional fix. To learn more about differences between security updates, optional non-security preview updates, out-of-band (OOB) updates, and continuous innovation, see Windows monthly updates explained. For information on Windows update terminology, see the different types of Windows software updates.

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

Improvements

This out-of-band (OOB) update includes quality improvements. This update is cumulative and includes security fixes and improvements from the January 13, 2026, security update (KB5073457) in addition to the following:

  • [Remote Desktop] Fixed: After installing the January 2026 Windows security update (KB5073457), some users experienced sign-in failures during Remote Desktop connections. This issue affected authentication steps for different Remote Desktop applications on Windows such as the Windows App.

If you installed earlier updates, your device downloads and installs only the new updates contained in this package.

Windows Server 2022 servicing stack update (KB5074428) -20348.4640

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

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. 

Symptom

After installing this update, some applications may become unresponsive or encounter unexpected errors when opening files from or saving files to cloud-based storage, such as OneDrive or Dropbox. In certain Outlook configurations that store PST files on OneDrive, Outlook may hang and fail to reopen unless the process is terminated or the system is restarted. Users may also see missing sent Items or previously downloaded emails being re‑downloaded.

Workaround

If you are experiencing this issue, please contact the application developer for possible alternative methods of accessing the files.

For Outlook-specific scenarios, moving the PST files out of OneDrive should resolve the issue. For guidance, please see documentation at How to remove an Outlook .pst data file from OneDrive. In addition, email accounts can still be accessed via webmail, if supported by your email provider.

Next steps

We are actively working on a resolution and will share an update as soon as more information becomes available.

How to get this update

Before you install this update

​​​​​​​Microsoft now combines the latest servicing stack update (SSU) for your operating system with the latest cumulative update (LCU). For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.

Install this update

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

Available

Next Step

Not included

See the Catalog option.

If you want to remove the LCU

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

For a list of the files provided in this update, download the file information for cumulative update 5077800. 

For a list of the files provided in the servicing stack update, download the file information for the SSU (KB5074428) - version 20348.4640. 

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