Table of contents

Release Date:



OS Build 17784.2005

Improvements and fixes

This security update includes quality improvements. Key changes include:

  • Addresses a known issue with virtual machines (VMs) that use Software Defined Networks (SDN) or traditional multi-tenant Routing and Remote Access service (RRAS) gateways. These VMs might lose connectivity with external networks that use gateway connections. This issue occurs after installing KB5005105 or a later Windows update.

For more information about the resolved security vulnerabilities, please refer to the Security Update Guide and the October 2021 Security Updates.

To return to the Azure Stack HCI documentation site

Known issues in this update

Microsoft is not currently aware of any issues with this update. 

How to get this update

The October 12, 2021 security update (KB5006679) for Azure Stack HCI is delivered from the release channels below. To install it on your Azure Stack HCI cluster, see Update Azure Stack HCI clusters.

Install this update 

Release Channel


Next Step

Windows Update and Microsoft Update


None. This update will be downloaded and installed automatically from Windows Update.

Windows Update for Business


None. This update will be downloaded and installed automatically from Windows Update in accordance with configured policies.

Microsoft Update Catalog


To get the standalone package for this update, go to the Microsoft Update Catalog website.

Windows Server Update Services (WSUS)


This update will automatically sync with WSUS if you configure Products and Classifications as follows:

Product: Azure Stack HCI

Classification: Security Updates

File Information

For a list of the files that are provided in this update, download the file information for cumulative update 5006679.

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