KB5071505 is the ESU Monthly Rollup Update for Windows Server 2012. It was released on 9 December 2025 under the ‘Patch Tuesday’ program.
Salient points
- KB5071505 supersedes KB5068907 released in November 2025.
- KB5071505 requires the KB5071813 Servicing Stack Update to be installed prior to installing the main monthly rollup update.
- Without the installation of KB5071813, the ESU KB5071505 cannot be installed. For WSUS administrators, KB5071813 needs to be approved before KB5071505 will be fetched and deployed automatically.
- If you install language pack after installing KB5071505, you would need to reinstall the security update. All language pack installations must be completed before installing the monthly rollup update on Windows Server 2012.
- KB5071505 is an Extended Security Update. A valid subscription key to the ESU program is required before installing the monthly rollup update.
- In December 2025, Microsoft disclosed 57 security vulnerabilities across all its products.
- Windows Server 2012 is impacted by 11 security vulnerabilities reported in December 2025 security bulletin.
- One zero-day vulnerability has been disclosed for Windows Server 2012 and Windows Server 2012 Server Core installation in December security bulletin released alongside the Windows Updates on 9 December 2025.
- The latest cumulative update for Internet Explorer 11 on Windows Server 2012 continues to be KB5066840 released in October 2025. So, new update for Internet Explorer is not needed in December 2025.
Servicing Stack Update KB5071813
The Servicing Stack Update for Windows Server 2012 for November 2025 is KB5071813. It corresponds to KB5068907 ESU and KB5071505 for December 2025.
For automated deployments of KB5071505 through the Windows Update program, the Servicing Stack Update KB5071813 is offered for installation as part of the installation process of the monthly rollup update KB5071505.
The Servicing Stack Update file is a small file around 10 MB size Upon installation, it would not cause server reboot.
Once the SSU is installed, you can proceed with the installation of the main monthly rollup update KB5071505.
Download KB5071505
You can download the monthly rollup update KB5071505 for Windows Server 2012 from the Windows Update Catalog page shared below:
We would reiterate that you need a valid ESU program subscription before you could install the ESU KB5071505 on Windows Server 2012.
Zero-day Vulnerabilities
One new zero-day security vulnerability has been reported for Windows Server 2012 and Windows Server 2012 Server Core installation in December month’s security bulletin released by Microsoft on 9 December 2025.
| CVE Details | CVSS Score | Comments |
|---|---|---|
| CVE-2025-54100 | 7.8 | Remote Code Execution Vulnerability in PowerShell (Windows) |
Internet Explorer Cumulative Update – KB5066840
To secure the Windows Server 2012, you also need to patch Internet Explorer 11 with the latest cumulative update. KB5066840 is the cumulative update for Internet Explorer released on 14 October 2025. No new security update for Internet Explorer 11 was released in November 2025.
You can download the IE Cumulative Update for Windows Server 2012 from the link shared below:
Download Cumulative Update for Internet Explorer – KB5066840 (54.9 MB)
KB5071505 – Changelog
Since this is an ESU, the focus remains on securing the Windows Server 2012 deployments. The following changes have been reported for KB5071505:
- [Internal Windows OS] Miscellaneous security improvements were made to internal Windows OS functionality.
- [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.
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