January 17, 2026—KB5077800 (OS Build 20348.4650) Out-of-band
Applies To
Release Date:
1/17/2026
Version:
OS Build 20348.4650
​​​​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.Â
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:
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[Remote Desktop]Â 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.Â
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.
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Available |
Next Step |
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See the Catalog option. |
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Available |
Next Step |
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See the Catalog option. |
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Available |
Next Step |
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Yes 1 |
To get the standalone package for this update, go to the Microsoft Update Catalog. |
1 This latest cumulative update includes updates for AI components. Even though the AI component updates are included in the update, the AI components are only applicable to Windows Copilot+ PCs and will not install on Windows PC or Windows Server.
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Available |
Next Step |
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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.Â
For a list of the files provided in the servicing stack update, download the file information for the SSU (KB5074428) - version 20348.4640.Â
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