MC1193628 – The December 2025 Windows security update is now available

Product:

Copilot, SharePoint, Windows, Windows Server

Platform:

Online, Windows Desktop, World tenant

Status:

Change type:

Admin impact

Links:

Details:

The December 2025 security update is now available for all supported versions of Windows. We recommend that you install these updates promptly. For more information about the contents of this update, see the release notes, which are easily accessible from the Windows 11 update history page. To learn more about the different types of monthly quality updates, see Windows monthly updates explained.

Highlights for the Windows 11, version 25H2 update:
This security update includes improvements that were a part of update KB5070311 (released December 1, 2025).
This update addresses security issues for your Windows operating system.
This update addresses an issue where Ask Copilot didn't activate the Click to Do* window as expected. The window now appears in the foreground when you share data with Copilot.
This update addresses an issue where File Explorer briefly flashes white when you navigate between pages. This issue might occur after you install KB5070311.
This update fixes an issue where external virtual switches lose their physical network adapter (NIC) bindings after a host restart.
* Experiences for Copilot+ PCs only


Short on time? Watch our Windows 11 release notes video for this month's tips.


For instructions on how to install this update, see the KB for your operating system listed below:
Windows 11, versions 25H2 and 24H2: KB5072033
Windows 11, version 23H2: KB5071417
Windows 11 Enterprise LTSC 2024: Hotpatch KB5072014
Windows 10, versions 22H2 and 21H2: KB5071546
Windows 10 Enterprise LTSC 2019 and Windows Server 2019: KB5071544
Windows 10 LTSB 2016 and Windows Server 2016: KB5071543
Windows Server 2025: KB5072033
Windows Server 2025 Datacenter: Azure Edition: Hotpatch KB5072014
Windows Server 2022: KB5071547
Windows Server 2022 Datacenter: Azure Edition: Hotpatch KB5071413
Windows Server 2012 R2: Monthly Rollup: KB5071503
Windows Server 2012: Monthly Rollup: KB5071505
Windows Server 2008 R2 Service Pack 1: Monthly Rollup: KB5071501 / Security Only: KB5071506
Windows Server 2008 SP2: Monthly Rollup: KB5071504 / Security Only: KB5071507


Note A separate standalone PowerShell update is available for the versions of Windows listed below and will be offered for devices using hotpatch updates. If any PowerShell components are active during installation, a system restart will be required to complete the update.
Windows 11, versions 24H2 and 25H2: KB5074204
Windows Server 2025: KB5074204
Windows Server 2022: KB5074353


IMPORTANT Because of minimal operations during the Western holidays and the upcoming new year, there will be no December 2025 non-security preview update in the second part of the month. Normal monthly servicing for both security and non-security preview updates will resume in January 2026.

Change Category:
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Scope:
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Release Phase:

Created:
2025-12-10

updated:
2025-12-10

Task Type

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Docu to Check

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MS Preperations

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MS Urgency

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MS workload name

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summary for non-techies**

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Direct effects for Operations**

Security Vulnerabilities
Failure to install the security update may leave systems exposed to known vulnerabilities, increasing the risk of cyber attacks.
   - roles: IT Security Manager, System Administrator
   - references: https://support.microsoft.com/help/5070311, https://support.microsoft.com/help/5071417

User Experience Degradation
Issues with Copilot activation and File Explorer flashing may lead to user frustration and decreased productivity.
   - roles: End User, Help Desk Support
   - references: https://support.microsoft.com/help/5070311, https://support.microsoft.com/help/5071546

Network Connectivity Issues
External virtual switches losing NIC bindings can disrupt network services, affecting applications reliant on network connectivity.
   - roles: Network Administrator, System Administrator
   - references: https://support.microsoft.com/help/5070311, https://support.microsoft.com/help/5071544

System Instability
Inadequate preparation for the update may result in system crashes or instability, leading to downtime.
   - roles: System Administrator, IT Support Specialist
   - references: https://support.microsoft.com/help/5071503, https://support.microsoft.com/help/5071504

Increased Support Tickets
Unprepared changes may lead to a surge in support requests from users experiencing issues post-update.
   - roles: Help Desk Support, IT Manager
   - references: https://support.microsoft.com/help/5070311, https://support.microsoft.com/help/5071547

Configutation Options**

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Opportunities**

Enhancing User Experience with Copilot
With the security update addressing the activation issue of the Click to Do window in Copilot, organizations can enhance user experience by ensuring that employees can efficiently use Copilot for task automation. This improvement can lead to increased productivity and reduced time spent on repetitive tasks.
   - next-steps: Communicate the benefits of the update to users, provide training sessions on using Copilot effectively, and gather feedback to further improve user experience.
   - roles: IT Managers, Productivity Specialists, End Users
   - references: https://support.microsoft.com/help/5070311, https://aka.ms/Windows11/ReleaseNotesVideo/2512

Improving Network Stability with Virtual Switch Fix
The update resolves issues with external virtual switches losing NIC bindings after host restarts. By implementing this fix, organizations can improve network stability for virtualized environments, reducing downtime and improving overall service reliability.
   - next-steps: Test the update in a controlled environment, monitor network performance post-implementation, and document any improvements or remaining issues.
   - roles: Network Administrators, System Administrators, IT Operations Managers
   - references: https://support.microsoft.com/help/5070311, https://support.microsoft.com/help/5072033

Streamlining IT Administrative Tasks
The update provides a separate standalone PowerShell update for various Windows versions. Utilizing PowerShell for automation can streamline IT administrative tasks, reducing manual workload and improving efficiency in managing updates across multiple systems.
   - next-steps: Develop scripts to automate the installation of updates using PowerShell, provide training for IT staff on PowerShell usage, and establish a schedule for regular updates to maintain system security.
   - roles: IT Administrators, DevOps Engineers, System Administrators
   - references: https://support.microsoft.com/help/5074204, https://support.microsoft.com/help/5071546

Potentional Risks**

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IT Security**

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explanation for non-techies**

The December 2025 Windows security update is now available, and it's a bit like getting a tune-up for your car. Just as a mechanic would check and fix any issues to ensure your car runs smoothly and safely, this update addresses security vulnerabilities and improves the performance of your Windows operating system.

One of the key fixes in this update is related to a feature called "Ask Copilot." Imagine you're trying to open a window on your computer, but it keeps popping up behind other windows, making it hard to see. This update ensures that the window appears in the foreground, much like making sure your car's windshield wipers are working properly so you can see clearly while driving.

Another fix involves File Explorer, which had a tendency to flash white briefly when switching between pages. Think of this like a flickering light in your home; it's not a major issue, but it can be annoying. The update is like replacing that flickering bulb with a new one, providing a smoother experience.

For those using virtual switches, the update also resolves an issue where these switches would lose their network connections after a restart. It's akin to ensuring that all your home appliances are plugged in correctly after a power outage, so everything works as it should.

The update is available for various versions of Windows, and it's important to install it to keep your system secure and efficient. It's like getting a regular health check-up; it helps prevent potential problems and keeps everything running in top condition.

For those short on time, there's a video available that highlights the key points of this update, much like a quick news recap that gives you the essentials without diving into all the details.

Lastly, due to the holiday season, there won't be a non-security preview update later in December, similar to how some services take a break during the holidays. Regular updates will resume in January, ensuring your system continues to receive the necessary attention and care.