October 13, 2020—KB4577671 (OS Builds 18362.1139 and 18363.1139)

Release Date:

Version:

10/13/2020

1903-OS Build 18362.1139 and 1909-OS Build 18363.1139

NEW
IMPORTANT Release notes are changing! To learn about the new URL, metadata updates, and more, see What’s next for Windows release notes.

NEW
IMPORTANT Windows 10, version 1903 will reach end of servicing on December 8, 2020. To continue receiving security and quality updates, Microsoft recommends that you update to the latest version of Windows 10. If you want to update to Windows 10, version 1909, you must use the Enablement Package KB4517245(EKB). Using the EKB makes updating faster and easier and requires a single restart. For more information, see Windows 10, version 1909 delivery options.

IMPORTANT Starting in July 2020, we will resume non-security releases for Windows 10 and Windows Server, version 1809 and later. There is no change to the cumulative monthly security updates (also referred to as the "B" release or Update Tuesday release). For more information, see the blog post Resuming optional Windows 10 and Windows Server non-security monthly updates.

IMPORTANT Starting in July 2020, all Windows Updates will disable the RemoteFX vGPU feature because of a security vulnerability. For more information about the vulnerability, seeCVE-2020-1036 and KB4570006. After you install this update, attempts to start virtual machines (VM) that have RemoteFX vGPU enabled will fail, and messages such as the following will appear:

If you re-enable RemoteFX vGPU, a message similar to the following will appear:

  • “The virtual machine cannot be started because all the RemoteFX-capable GPUs are disabled in Hyper-V Manager.”

  • “The virtual machine cannot be started because the server has insufficient GPU resources.”

  • "We no longer support the RemoteFX 3D video adapter. If you are still using this adapter, you may become vulnerable to security risk. Learn more (https://go.microsoft.com/fwlink/?linkid=2131976)”

What's new for Windows 10, version 1909 and Windows 10, version 1903 release notes

Windows 10, versions 1903 and 1909 share a common core operating system and an identical set of system files. As a result, the new features in Windows 10, version 1909 were included in the recent monthly quality update for Windows 10, version 1903 (released October 8, 2019), but are currently in a dormant state. These new features will remain dormant until they are turned on using an enablement package, which is a small, quick-to-install “master switch” that simply activates the Windows 10, version 1909 features.

To reflect this change, the release notes for Windows 10, version 1903 and Windows 10, version 1909 will share an update history page. Each release page will contain a list of addressed issues for both 1903 and 1909 versions. Note that the 1909 version will always contain the fixes for 1903; however, 1903 will not contain the fixes for 1909. This page will provide you with the build numbers for both 1909 and 1903 versions so that it will be easier for support to assist you if you encounter issues.

For more details about the enablement package and how to get the feature update, see the Windows 10, version 1909 delivery options blog.

For more information about the various types of Windows updates, such as critical, security, driver, service packs, and so on, please see the following article.

Note Follow @WindowsUpdate to find out when new content is published to the release information dashboard.

Highlights

  • Updates to improve security when using Microsoft Office products.

  • Updates for verifying usernames and passwords.

  • Updates to improve security when Windows performs basic operations.

  • Updates for storing and managing files.

Improvements and fixes

This security update includes quality improvements. Key changes include:

  • This build includes all the improvements from Windows 10, version 1903.

  • No additional issues were documented for this release.

Note This release also contains updates for Microsoft HoloLens (OS Build 18362.1081) released October 13, 2020. Microsoft will release an update directly to the Windows Update Client to improve Windows Update reliability on Microsoft HoloLens that have not updated to this most recent OS Build.

This security update includes quality improvements. Key changes include:

  • Addresses an issue with a possible elevation of privilege in win32k.

  • Addresses an issue with the Group Policy service that might recursively delete critical files in alphabetic order from %systemroot%\system32. This issue occurs when a policy has been configured to delete cached profiles. These file deletions might cause stop error “0x5A (CRITICAL_SERVICE_FAILED)” boot failures.

  • Addresses an issue with creating null ports using the user interface.

  • Security updates to Windows App Platform and Frameworks, Microsoft Graphics Component, Windows Media, Windows Shell, Windows Cloud Infrastructure, Windows Fundamentals, Windows Authentication, Windows Virtualization, Windows Kernel, and Windows Storage and Filesystems.

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

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

Windows Update Improvements

Microsoft has released an update directly to the Windows Update client to improve reliability. Any device running Windows 10 configured to receive updates automatically from Windows Update, including Enterprise and Pro editions, will be offered the latest Windows 10 feature update based on device compatibility and Windows Update for Business deferral policy. This doesn't apply to long-term servicing editions.

Known issues in this update

Symptom

Workaround

When updating to Windows 10, version 1903 or Windows 10, version 1909 from any previous version of Windows 10, you might receive a compatibility report dialog with "What needs your attention" at the top and the error, "Continuing with the installation of Windows will remove some optional features. You may need to add them back in Settings after the installation completes." You might receive this compatibility warning when LOCAL SYSTEM accounts are blocked in a firewall from accessing the internet via HTTP. This is caused by the Windows 10 Setup Dynamic Update (DU) being unable to download required packages.

This issue is resolved in KB4579919.

When installing a third-party driver, you might receive the error, “Windows can’t verify the publisher of this driver software”. You might also see the error, “No signature was present in the subject” when attempting to view the signature properties using Windows Explorer.

This issue occurs when one or more of the following is present in a driver package:

  • An improperly formatted catalog file is identified during validation by Windows. Starting with this release, Windows will require the validity of DER encoded PKCS#7 content in catalog files. Catalogs files must be signed per section 11.6 of describing DER-encoding for SET OF members in X.690.

  • A driver catalog file extension is not one of supported extensions.

If this happens you should contact the driver vendor or device manufacturer (OEM) and ask them for an updated driver to correct the issue.

System and user certificates might be lost when updating a device from Windows 10, version 1809 or later to a later version of Windows 10. Devices will only be impacted if they have already installed any Latest cumulative update (LCU) released September 16, 2020 or later and then proceed to update to a later version of Windows 10 from media or an installation source which does not have an LCU released October 13, 2020 or later integrated. This primarily happens when managed devices are updated using outdated bundles or media through an update management tool such as Windows Server Update Services (WSUS) or Microsoft Endpoint Configuration Manager. This might also happen when using outdated physical media or ISO images that do not have the latest updates integrated.

Note Devices using Windows Update for Business or that connect directly to Windows Update are not impacted. Any device connecting to Windows Update should always receive the latest versions of the feature update, including the latest LCU, without any extra steps.

 If you have already encountered this issue on your device, you can mitigate it within the uninstall window by going back to your previous version of Windows using the instructions here. The uninstall window might be 10 or 30 days depending on the configuration of your environment and the version you’re updating to. You will then need to update to the later version of Windows 10 after the issue is resolved in your environment. Note Within the uninstall window, you can increase the number of days you have to go back to your previous version of Windows 10 by using the DISM command /Set-OSUninstallWindow. You must make this change before the default uninstall window has lapsed. For more information, see DISM operating system uninstall command-line options.

 

We are working on a resolution and will provide updated bundles and refreshed media in the coming weeks.

How to get this update

Before installing this update

Microsoft strongly recommends you install the latest servicing stack update (SSU) for your operating system before installing the latest cumulative update (LCU). SSUs improve the reliability of the update process to mitigate potential issues while installing the LCU and applying Microsoft security fixes. For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.

If you are using Windows Update, the latest SSU (KB4577670) will be offered to you automatically. To get the standalone package for the latest SSU, search for it in the Microsoft Update Catalog.

Install this update

Release Channel

Available

Next Step

Windows Update and Microsoft Update

Yes

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

Microsoft Update Catalog

Yes

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

Windows Server Update Services (WSUS)

Yes

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

Product: Windows 10, version 1903 and later

Classification: Security Updates

 

File information

For a list of the files that are provided in this update, download the file information for cumulative update 4577671

Note Some files erroneously have “Not applicable” in the “File version” column of the CSV file. This might lead to false positives or false negatives when using some third-party scan detection tools to validate the build.

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