December 2020 Security Updates




The December security release consists of security updates for the following software:



  • Microsoft Windows
  • Microsoft Edge (EdgeHTML-based)
  • Microsoft Edge for Android
  • ChakraCore
  • Microsoft Office and Microsoft Office Services and Web Apps
  • Microsoft Exchange Server
  • Azure DevOps
  • Microsoft Dynamics
  • Visual Studio
  • Azure SDK
  • Azure Sphere

Please note the following information regarding the security updates:



  • See our blog detailing the benefits of the new Security Update Guide layout here.
  • Microsoft is improving Windows Release Notes. For more information, please see What's next for Windows release notes.
  • For information regarding enabling Windows 10, version 2004 features, please see Windows 10, version 20H2 delivery options. Note that Windows 10, versions 2004 and 20H2 share a common core operating system with an identical set of system files. They will also share the same security update KBs.
  • For information regarding enabling Windows 10, version 1909 features, please see Windows 10, version 1909 delivery options. Note that Windows 10, versions 1903 and 1909 share a common core operating system with an identical set of system files. They will also share the same security update KBs.
  • Windows 10 updates are cumulative. The monthly security release includes all security fixes for vulnerabilities that affect Windows 10, in addition to non-security updates. The updates are available via the Microsoft Update Catalog.
  • For information on lifecycle and support dates for Windows 10 operating systems, please see Windows Lifecycle Facts Sheet.
  • A list of the latest servicing stack updates for each operating system can be found in ADV990001. This list will be updated whenever a new servicing stack update is released. It is important to install the latest servicing stack update.
  • Updates for Windows RT 8.1 and Microsoft Office RT software are only available via Windows Update.
  • In addition to security changes for the vulnerabilities, updates include defense-in-depth updates to help improve security-related features.
  • Customers running Windows 7, Windows Server 2008 R2, or Windows Server 2008 need to purchase the Extended Security Update to continue receiving security updates. See 4522133 for more information.

The following CVEs have FAQs with additional information and may include * further steps to take after installing the updates. Please note that this is not a complete list of CVEs for this release.




Known Issues


The following KBs contain information about known issues with the security updates. For a complete list of security update KBs, please see 20201208. For more information about Windows Known Issues, please see Windows message center (links to currently-supported versions of Windows are in the left pane).


KB Article Applies To
4592438 Windows 10, version 2004, Windows Server version 2004, Windows 10, version 20H2, Windows Server version 20H2
4592440 Windows 10 Version 1809, Windows Server 2019
4592449 Windows 10, version 1903, Windows Server version 1903, Windows 10, version 1909, Windows Server version 1909
4592468 Windows Server 2012 (Monthly Rollup)
4592471 Windows 7, Windows Server 2008 R2 (Monthly Rollup)
4592484 Windows 8.1, Windows Server 2012 R2 (Monthly Rollup)
4592495 Windows 8.1, Windows Server 2012 R2 (Security-only update)
4592497 Windows Server 2012 (Security-only update)
4592498 Windows Server 2008 (Monthly Rollup)
4592503 Windows 7, Windows Server 2008 R2 (Security-only update)
4592504 Windows Server 2008 (Security-only update)
4593226 Windows 10, version 1607, Windows Server 2016
4593465 Exchange Server 2019, Exchange Server 2016
4593466 Exchange Server 2013
4593467 Exchange Server 2010 Service Pack 3


December 2020 Security Updates - Release Notes - Security Update Guide - Microsoft