KB5077793: This OOB update includes quality improvements

January 17, 2026—KB5077793 (OS Build 26100.32234) Out-of-band

This out-of-band update for Windows Server 2025 (KB5077793) is cumulative. It includes updates from previous security releases, 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 2025.

Improvements
This OOB update includes quality improvements. This update is cumulative and includes security fixes and improvements from the January 13, 2026, security update (KB5073379) in addition to the following:

• [Remote Desktop] Fixed: After installing the January 2026 Windows security update (KB5073379), 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.