Update01/14/2026

KB5073450: This update addresses an issue that affects apps such as Outlook, Teams, Edge,

Windows Server 23H2
Microsoft

January 13, 2026—KB5073450 (OS Build 25398.2092)

This cumulative update for Windows Server, version 23H2 (KB5073450), includes the latest security fixes and improvements, along with non-security updates from last month’s optional preview release. 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 update history page for Windows Server, version 23H2.

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

Improvements
This security update contains fixes and quality improvements from KB5071542 (released December 9, 2025). The following summary outlines key issues addressed by this update. Also, included are available new features. The bold text within the brackets indicates the item or area of the change.

- [Compatibility] This update removes the following modem drivers: agrsm64.sys (x64), agrsm.sys (x86), smserl64.sys (x64) and smserial.sys (x86). Modem hardware dependent on these specific drivers will no longer work in Windows.

[Input] Fixed: This update addresses an issue that affects apps such as Outlook, Teams, Edge, Chrome, and Excel. These apps might close unexpectedly when you enter text.
[Windows Deployment Services (WDS] This update introduces a change in behavior in which WDS will stop supporting hands-free deployment functionality by default. Detailed guidance for IT administrators is available in Windows Deployment Services (WDS) Hands‑Free Deployment Hardening Guidance.

- [WinSqlite3.dll] Fixed: The Windows core component, WinSqlite3.dll, has been updated. Previously, some security software might have detected this component as vulnerable.