Microsoft Windows Server 2025 Update Version OS Build 26100.32230

KB5073379 for Windows Server 2025 installs the January 13, 2026 cumulative update for OS Build 26100.32230, including security fixes, quality improvements, and changes from the December preview. It also adds Secure Boot targeting data, hardens credential autofill behavior, and removes legacy modem drivers.

• Introduces security hardening for Credentials autofill by restricting certain applications during remote support sessions or automated authentication workflows.
• Includes security fixes from the January 2026 security update and addresses a Windows core component detection issue for WinSqlite3.dll.
• WSUS synchronization error details are temporarily removed to address CVE-2025-59287.

• Fixes RemoteApp connection failures in Azure Virtual Desktop environments after KB5072033.
• Fixes an issue where devices that installed KB5070881 stopped receiving Hotpatch updates.
• Updates WinSqlite3.dll to address false vulnerability detections by some security software.

• Adds high-confidence device targeting data to help automatically deliver new Secure Boot certificates in a phased rollout.
• Changes Windows Deployment Services so hands-free deployment functionality is no longer supported by default.

• WSUS does not display synchronization error details after KB5070881 or later updates.
• Credential prompt failures may occur in Azure Virtual Desktop and Windows 365 when using the Windows App on some Windows client builds; addressed in KB5077793.
• Some apps may become unresponsive or error when opening or saving files in cloud-based storage such as OneDrive or Dropbox.

• Starting with January 2026, Windows Server 2025 uses its own KB identifiers and build numbers, separate from Windows 11 versions 24H2 and 25H2.
• Legacy modem drivers agrsm64.sys, agrsm.sys, smserl64.sys, and smserial.sys are removed; hardware depending on them will no longer work.
• Secure Boot certificates used by most Windows devices are set to expire starting in June 2026; administrators should review certificate update guidance.
• If Outlook PST files are stored on OneDrive, moving them out of OneDrive may resolve the cloud-storage save/open issue.

Product Information

Vendor: Microsoft

Product: Windows Server 2025

Product type: Software

Application category: Utilities

Platform: Windows

Version: OS Build 26100.32230

Vendor release date: Jan 13, 2026

Original release notes: View on vendor site

Published on updatealert.io: Jun 3, 2026

Description: Server operating system for next-generation on-premises and hybrid workloads.