January 13, 2026—KB5073379 (OS Build 26100.32230)
Applies To
Windows Server 2025, all editions
Release Date:
1/13/2026
Version:
OS Build 26100.32230
This cumulative update for Windows Server 2025 (KB5073379), 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 Windows release health dashboard or the update history page for Windows Server 2025.
This section provides key notifications related to this release, including announcements, change logs, and end-of-support notices.
Starting with the January 2026 security update, Windows Server 2025 will have its own KB identifiers and build numbers. These identifiers are separate from those for Windows 11 versions 24H2 and 25H2. This change improves clarity for administrators. Installation and management processes remain the same.
Windows Secure Boot certificate expiration
Important: Secure Boot certificates used by most Windows devices are set to expire starting in June 2026. This might affect the ability of certain personal and business devices to boot...
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