September 8, 2020—KB4577015 (OS Build 14393.3930)

IMPORTANT Windows 10, version 1607 has reached the end of mainstream support and is now in extended support. Starting in July 2020, there will no longer be optional, non-security releases (known as "C" releases) for this operating system. Operating systems in extended support have only cumulative monthly security updates (known as the "B" or Update Tuesday release).

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)”

Reminder The additional servicing for Windows 10 Enterprise, Education, and IoT Enterprise editions ended on April 9, 2019 and doesn't extend beyond this date. To continue receiving security and quality updates, Microsoft recommends updating to the latest version of Windows 10.

Reminder March 12, 2019 and April 9, 2019 were the last two Delta updates for Windows 10, version 1607. For Long-Term Servicing Branch (LTSB) customers, security and quality updates will continue to be available via the express and full cumulative update packages. For more information on this change please visit our blog.

Windows 10, version 1607, reached end of service on April 10, 2018. Devices running Windows 10 Home or Pro editions will no longer receive monthly security and quality updates that contain protection from the latest security threats. To continue receiving security and quality updates, Microsoft recommends updating to the latest version of Windows 10.

IMPORTANTWindows 10 Enterprise and Windows 10 Education editions will receive additional servicing at no cost until April 9, 2019. Devices on the Long-Term Servicing Channels (LTSC) will continue to receive updates until October 2026 per the Lifecycle Policy page. Windows 10 Anniversary Update (v. 1607) devices running the Intel “Clovertrail” chipset will continue to receive updates until January 2023 per the Microsoft Community blog.

Windows Server 2016 Standard edition, Nano Server installation option and Windows Server 2016 Datacenter edition, Nano Server installation option reached end of service on October 9, 2018. These editions will no longer receive monthly security and quality updates that contain protection from the latest security threats. To continue receiving security and quality updates, Microsoft recommends updating to the latest version of Windows 10.

Windows 10 Mobile, version 1607, reached end of service on October 8, 2018. Devices running Windows 10 Mobile and Windows 10 Mobile Enterprise will no longer receive monthly security and quality updates that contain protection from the latest security threats. To continue receiving security and quality updates, Microsoft recommends updating to the latest version of Windows 10.

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.

Highlights

Updates time zone information for the Yukon, Canada.
Updates to improve security when using Microsoft Office products.
Updates to improve security in the Microsoft Store.
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:

Provides the ability to set a Group Policy that displays only the domain and username when you sign in.
Updates time zone information for the Yukon, Canada.
Addresses an issue that prevents the Event Viewer from properly saving filtered events.
Addresses an issue with object performance counters.
Addresses an issue that sometimes prevents AppLocker from running an application whose publisher rule allows it to run.
Addresses an issue that causes delays during shutdown when running the Microsoft Keyboard Filter Service.
Addresses a security vulnerability issue with user proxies and HTTP-based intranet servers. After installing this update, HTTP-based intranet servers cannot leverage a user proxy by default to detect updates. Scans using these servers will fail if the clients do not have a configured system proxy. If you must leverage a user proxy, you must configure the behavior using the Windows Update policy “Allow user proxy to be used as a fallback if detection using system proxy fails.” This change does not affect customers who secure their Windows Server Update Services (WSUS) servers with the Transport Layer Security (TLS) or Secure Sockets Layer (SSL) protocols. For more information, see Improving security for devices receiving updates via WSUS.
Addresses an issue with evaluating the compatibility status of the Windows ecosystem to help ensure application and device compatibility for all updates to Windows.
Addresses an issue that might prevent a client from reconnecting to a previous RemoteApp session unless an administrator closes the session on the server.
Security updates to Windows App Platform and Frameworks, Microsoft Graphics Component, Windows Input and Composition, Windows Media, Windows Shell, the Microsoft Store, Windows Cloud Infrastructure, Windows Fundamentals, Windows Kernel, Windows Virtualization, Windows Storage and Filesystems, the Microsoft Scripting Engine, and the Microsoft JET Database Engine.

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

After installing KB4467684, the cluster service may fail to start with the error “2245 (NERR_PasswordTooShort)” if the group policy “Minimum Password Length” is configured with greater than 14 characters.

Set the domain default "Minimum Password Length" policy to less than or equal to 14 characters.

Microsoft is working on a resolution and will provide an update in an upcoming release.

Accessing the Security Options data view in the Group Policy Management Editor (gpedit.msc) or Local Security Policy Editor (secpol.msc) might fail with the error "MMC has detected an error in a snap-in. It is recommended that you shut down and restart MMC" or “MMC cannot initialize the snap-in”. This occurs from the MMC window, when the console tree is expanded in the following sequence: select Computer Configuration, then Policies, then Windows Settings, then Security Settings, then Local Policies, then Security Options.

The resulting error dialog provides options to continue using the Management Console to view other nodes normally. Note: This issue does not affect the application of the Security Options or any other Group Policy Objects (GPOs) to devices in your environment.

This issue is resolved in KB4580346.

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 (KB4576750) 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 Classification: Security Updates

File information

For a list of the files that are provided in this update, download the file information for cumulative update 4577015.

September 8, 2020—KB4577015 (OS Build 14393.3930)

Highlights

Improvements and fixes

Known issues in this update

How to get this update

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