September 8, 2020—KB4571756 (OS Build 19041.508)

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)”

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.

Note This release also contains updates for Microsoft HoloLens (OS Build 19041.1117) released September 8, 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.

Highlights

Updates to improve security when using input devices (such as a mouse, keyboard, or pen).
Updates to improve security when Windows performs basic operations.
Updates for storing and managing files.
Updates to improve security when using Microsoft Office products.

Improvements and fixes

This security update includes quality improvements. Key changes include:

Addresses an issue with a possible elevation of privilege in windowmanagement.dll.
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.
Security updates to Windows App Platform and Frameworks, Microsoft Graphics Component, Windows Input and Composition, Windows Media, Windows Shell, Windows Cloud Infrastructure, Windows Fundamentals, Windows Management, 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
Users of the Microsoft Input Method Editor (IME) for Japanese or Chinese languages might experience issues when attempting various tasks. You might have issues with input, receive unexpected results, or might not be able to enter text.	All IME issues listed in KB4564002 were resolved in KB4586853.

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 (KB4577266) will be offered to you automatically. To get the standalone package for the latest SSU, search for it in the Microsoft Update Catalog.

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 4571756.

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.

September 8, 2020—KB4571756 (OS Build 19041.508)

Highlights

Improvements and fixes

Known issues in this update

How to get this update

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