KB5071544 is the cumulative update for Windows Server 2019 and Windows Server 2019 Server Core installation. It was released on 9 December, 2025 under the ‘Patch Tuesday’ release cycle.
Salient points
- KB5071544 supersedes November 2025 cumulative update KB5068791.
- KB5071544 corresponds to Windows server build 17763.8146.
- Two Zero-day vulnerabilities affect Windows Server 2019 and Windows Server 2019 Server Core installation as per December’s security bulletin.
- 57 security vulnerabilities have been disclosed for December 2025 by Microsoft. 29 of these affect Windows Server 2019 and Windows Server 2019 Server Core installation.
- The Servicing Stack Update corresponding to KB5071544 is KB5070248 (17763.8020). It is in-built in the main cumulative update. Separate installation of the SSU or Servicing Stack is not needed.
- KB5005112 is the SSU that must be already deployed on Windows Server 2019. If you have not deployed this SSU, please download KB5005112 and apply on the server. This is a very old SSU released in August 2021. If you have followed the update release cycle, there is a high chance that you already have this patch on the server. SSU installation does not cause server reboot.
Important Reminders
Apart from this, it is important to note that the Secure Boot certificates used by most Windows devices are set to expire starting in June 2026. Secure Boot is a security feature in Unified Extensible Firmware Interface (UEFI) based firmware that helps ensure that only trusted software runs during a device’s boot (start) sequence.
Since Windows introduced Secure Boot support, all Windows-based devices have carried the same set of Microsoft certificates in the KEK and DB. These original certificates are nearing their expiration date, and your device is affected if it has any of the listed certificate versions. To continue running Windows and receiving regular updates for your Secure Boot configuration, you will need to update these certificates.
Download KB5070248
KB5070248 is the Servicing Stack Update for Windows Server 2019 released in November 2025 alongside the main cumulative update KB5068791. This same Servicing Stack Update is to be used for December 2025 security update for Windows Server 2019, KB5071544.
If you intend to deploy cumulative updates through Windows Update or Windows Update for Business, no action is needed to install the Servicing Stack Update. The Servicing Stack Update is part of the security update that will be installed on Windows Server 2019.
For manual installation of KB5071544, there is no separate installation of KB5070248 as it is included in the main cumulative security update.
Download KB5071544
You may download the offline installer file for KB5071544 from the catalog site link shared below:
Upon installation of KB5071544, the server would restart. The Servicing Stack Update is already included in the main update and will be downloaded and installed as part of the installation process.
Zero-day vulnerabilities
Two zero-day vulnerability has been reported for Windows Server 2019 in December 2025.
| CVE Details | CVSS Score | Comments |
|---|---|---|
| CVE-2025-62221 | 7.8 | Elevation of Privilege Vulnerability IN Windows Cloud Files Mini Filter Driver |
| CVE-2025-54100 | 7.8 | Remote Code Execution Vulnerability in PowerShell (Windows) |
Critical vulnerabilities
The December security bulletin for Windows Server 2019 reports 29 security vulnerabilities. There are no CRITICAL vulnerabilities affecting Windows Server 2019.
Changelog – KB5071544
The following changes or improvements are part of KB5071544 for Windows Server 2019:
- The update addresses security improvements for Windows Server 2019 and Windows Server 2019 Server Core installation.
- [Internal Windows OS] This update contains miscellaneous security improvements to internal Windows OS functionality. No specific issues are documented for this release.
- [PowerShell 5.1] The Invoke-WebRequest command now includes a confirmation prompt with a security warning of a script execution risk. You can choose to continue or cancel the request. For additional details, see CVE-2025-54100 and KB5074596: PowerShell 5.1: Preventing script execution from web content.
- [People app] After installing this update, the People icon on the taskbar will no longer respond. This feature is being deprecated in Windows Server 2019 and Windows 10, version 1809.
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