Patch Review Recommendations

Flexis December 2025 Patch Recommendation

Patches Microsoft released in December 2025

 

  • KB5071547: 2025-12 Cumulative Update for Microsoft server operating system version 21H2 for x64-based Systems
  • KB5071544: 2025-12 Cumulative Update for Windows Server 2019 for x64-based Systems
  • KB5071543: 2025-12 Cumulative Update for Windows Server 2016 for x64-based Systems

Impacted Products:

Microsoft-Windows

Microsoft Windows

Microsoft-Edge

Microsoft Edge

(HTML-based)

Microsoft-Edge

Microsoft Edge

 (Chromium-based)

Internet-Explorer

Internet Explorer

Microsoft-Office

Microsoft Office and Microsoft Office Services and Web Apps

Windows-Defenser

Windows Defender

Visual-Studio

Visual Studio

6

ASP.NET Core

Untitled design (1)

Chakra Core

Microsoft-Dynamics

Microsoft Dynamics

NET-Framework

.NET Framework

NET-Core

.NET Core

Please note the following information regarding the security updates:

Windows 10 Enterprise and Education and Windows 10 Home and Pro Lifecycle pages, Windows 10 was ended on October 14, 2025. The current version, 22H2, will be the final version of Windows 10. The following editions will remain in support with monthly security update releases through that date:

Home

Pro

Pro Education

Pro for Workstations

Education

Enterprise

Enterprise multi-session

KB5071547: Windows Server 2022

Improvements

This security update contains fixes and quality improvements from KB5068787 (released November 11, 2025). The following summary outlines key issues addressed by this update. Also, included are available new features. The bold text within the brackets indicates the item or area of the change.

Known issues in this update

After installing KB5070884 or later updates, Windows Server Update Services (WSUS) does not display synchronization error details within its error reporting. This functionality is temporarily removed to address the Remote Code Execution Vulnerability, CVE-2025-59287.

KB5071544: Windows Server 2019 Win 10 Ent LTSC 2019

Windows Secure Boot certificate expiration

Important: Secure Boot certificates used by most Windows devices are set to expire starting in June 2026. This might affect the ability of certain personal and business devices to boot securely if not updated in time. To avoid disruption, we recommend reviewing the guidance and taking action to update certificates in advance. For details and preparation steps, see Windows Secure Boot certificate expiration and CA updates.

Summary

Windows 10 , Version 1809

Applies to: Windows 10 Enterprise LTSC 2021

Applies to: Win 10 Ent LTSC 2019

This security update includes fixes and quality improvements that are part of the following update:

The following is a summary of the issues that this update addresses when you install this update. The bold text within the brackets indicates the item or area of the change we are documenting.

If you installed earlier updates, only the new updates contained in this package will be downloaded and installed on your device.

 

Windows Server 2019

Applies to: Windows Server 2019 (All editions)

Applies to: Windows Server 2019

This security update includes fixes and quality improvements that are part of the following update:

The following is a summary of the issues that this update addresses when you install this update. The bold text within the brackets indicates the item or area of the change we are documenting.

 Known issues in this update​​​​​​​ for Windows Server 2019

 

​​​​​​​ Symptoms

After installing this update, users might face issues with the Message Queuing (MSMQ) functionality. This issue also impacts clustered MSMQ environments under load. Due to this issue, users might encounter the following symptoms:

  • MSMQ queues becoming inactive
  • IIS sites failing with “Insufficient resources to perform operation” errors
  • Applications unable to write to queues
  • Errors such as “The message file ‘C:\Windows\System32\msmq\storage*.mq’ cannot be created” when creating message files
  • Misleading logs, such as “There is insufficient disk space or memory”, despite sufficient disk space and memory being available

This issue is caused by the recent changes introduced to the MSMQ security model and NTFS permissions on the C:\Windows\System32\MSMQ\storage folder. MSMQ users now require write access to this folder, which is normally restricted to administrators. As a result, attempts to send messages via MSMQ APIs might fail with resource errors.

 

 

Known issues in this update​​​​​​​ for Windows 10 , Version 1809

 

Symptoms

After installing this update, users might face issues with the Message Queuing (MSMQ) functionality. This issue also impacts clustered MSMQ environments under load. Due to this issue, users might encounter the following symptoms:

  • MSMQ queues becoming inactive
  • IIS sites failing with “Insufficient resources to perform operation” errors
  • Applications unable to write to queues
  • Errors such as “The message file ‘C:\Windows\System32\msmq\storage*.mq’ cannot be created” when creating message files
  • Misleading logs, such as “There is insufficient disk space or memory”, despite sufficient disk space and memory being available

This issue is caused by the recent changes introduced to the MSMQ security model and NTFS permissions on the C:\Windows\System32\MSMQ\storage folder. MSMQ users now require write access to this folder, which is normally restricted to administrators. As a result, attempts to send messages via MSMQ APIs might fail with resource errors.

KB5071543: Windows Server 2016, all editions Win 10 Ent LTSB 2016

Support for Windows 10 ended on 14th October 2025

After October 14, 2025, Microsoft will no longer provide free software updates from Windows Update, technical assistance, or security fixes for Windows 10. Your PC will still work, but we recommend moving to Windows 11.

Windows Secure Boot certificate expiration

Important: Secure Boot certificates used by most Windows devices are set to expire starting in June 2026. This might affect the ability of certain personal and business devices to boot securely if not updated in time. To avoid disruption, we recommend reviewing the guidance and taking action to update certificates in advance. For details and preparation steps, see Windows Secure Boot certificate expiration and CA updates.

Summary

This servicing stack update (SSU) makes quality improvements to the servicing stack, which is the component that installs Windows updates. Servicing stack updates make sure that you have a robust and reliable servicing stack so that your devices can receive and install Microsoft updates.

Important Not installing the latest SSU before applying Windows updates might result in the Windows update not being offered until the latest SSU is installed. 

Applies to: Windows Server 2016

This security update includes fixes and improvements that are a part of the following update:

The following is a summary of the issues that this update addresses. The bold text within the brackets indicates the item or area of the change we are documenting.

If you installed earlier updates, only the new updates contained in this package will be downloaded and installed on your device.

Applies to: Win 10 Ent LTSB 2016

This security update includes fixes and improvements that are a part of the following update:

The following is a summary of the issues that this update addresses. The bold text within the brackets indicates the item or area of the change we are documenting.

If you installed earlier updates, only the new updates contained in this package will be downloaded and installed on your device.

 

Known issues in this update

 

Symptoms

After installing this update, users might face issues with the Message Queuing (MSMQ) functionality. This issue also impacts clustered MSMQ environment under load. Due to this issue, users might encounter the following symptoms:

  • MSMQ queues becoming inactive
  • IIS sites failing with “Insufficient resources to perform operation” errors
  • Applications unable to write in queues
  • Errors such as “The message file ‘C:\Windows\System32\msmq\storage*.mq’ cannot be created” when creating message files
  • Misleading logs, such as “There is insufficient disk space or memory”, despite sufficient disk space and memory being available

This issue is caused by the recent changes introduced to the MSMQ security model and NTFS permissions on the C:\Windows\System32\MSMQ\storage folder. MSMQ users now require write access to this folder, which is normally restricted to administrators. As a result, attempts to send messages via MSMQ APIs might fail with resource errors.