Table of Contents
- What are the critical security fixes included in the December 2025 Windows Server Patch Tuesday?
- Critical Operational Advisory: PowerShell 5.1 Changes
- Detailed Update Breakdown by Version
- Windows Server 2025 Update: KB5072033
- Windows Server 2022 and 23H2
- Windows Server 2016 and 2019
- Windows Server 2012 and 2012 R2
- Recommendations for Deployment
What are the critical security fixes included in the December 2025 Windows Server Patch Tuesday?
As we close out the year, Microsoft has released the December 2025 Patch Tuesday cumulative updates. This rollout addresses significant security vulnerabilities across the entire Windows Server ecosystem, from Server 2012 to the latest Server 2025.
As your technical advisor, I must draw your attention to a specific change in PowerShell 5.1 included in this patch cycle. This change alters how scripts interact with web content and could potentially disrupt your automated workflows if not reviewed.
Critical Operational Advisory: PowerShell 5.1 Changes
Applies to: Windows Server 2012 through 2025
The most impactful change in this month’s cycle involves the Invoke-WebRequest command in PowerShell 5.1. Microsoft has introduced a mandatory confirmation prompt to mitigate security risks associated with executing scripts from the web (CVE-2025-54100).
The Change: When you run Invoke-WebRequest, the system will now pause and ask you to confirm or cancel the request.
The Risk: If you utilize “headless” or unattended scripts that rely on this command for background tasks, they may hang indefinitely waiting for user input that will never come.
Action Required: Audit your automation scripts immediately. You may need to modify your command syntax to bypass this prompt or adjust your execution policies. Refer to KB5074596 for specific mitigation strategies.
Detailed Update Breakdown by Version
Windows Server 2025
Update: KB5072033
For those running the latest infrastructure, Microsoft has released KB5072033. This cumulative update focuses on hardening the OS against recent threat vectors.
Deployment: The update includes the latest Servicing Stack Update (SSU). Windows Update will install this automatically, but you can also source it from WSUS, Windows Update for Business (WUfB), or the Microsoft Update Catalog.
Windows Server 2022 and 23H2
Administrators managing these versions must select the correct KB based on their specific build.
- Windows Server 23H2 (KB5071542): This update includes the critical PowerShell security prompt mentioned above. Ensure your maintenance windows account for testing Invoke-WebRequest behaviors.
- Windows Server 2022 (KB5071547): This package mirrors the security patches found in the 23H2 update. It resolves various bugs and enforces the new PowerShell script execution warning.
Windows Server 2016 and 2019
These stable workhorses receive important lifecycle changes alongside security fixes.
Windows Server 2019 (KB5071544):
- Feature Deprecation: The “People” app icon on the taskbar is now deprecated. Following this installation, the icon will cease to function. This is an intentional removal of features dating back to Windows 10, version 1809.
- Security: Includes the PowerShell 5.1 fix.
Windows Server 2016 (KB5071543):
- Focuses primarily on security hardening and the PowerShell Invoke-WebRequest modification.
- Advisory: Pay close attention to the installation sequence. You must install the Service Stack Update (SSU) before the cumulative update to avoid potential corruption or rollback loops.
Windows Server 2012 and 2012 R2
Prerequisite: Extended Security Updates (ESU) License.
Support for these operating systems officially ended in October 2023. You will not receive these patches via standard channels unless your organization has purchased an active ESU license.
Windows Server 2012 R2 (KB5071503): This Monthly Rollup reinforces security for legacy systems. It includes the PowerShell confirmation prompt change.
Windows Server 2012 (KB5071505): Similar to R2, this update patches critical vulnerabilities.
- Installation Note: You must install the latest SSU prior to this update. Once installed, the SSU cannot be removed.
Recommendations for Deployment
- Test First: given the change to Invoke-WebRequest, do not deploy these updates to production without testing your essential scripts in a sandbox environment.
- Verify Backups: Ensure your backup integrity is confirmed before applying cumulative updates.
- Check SSUs: Always verify that the Serving Stack Update is applied first if you are manually managing the installation order.