November 10, 2020—KB4586781 (OS Builds 19041.630 and 19042.630)

NEW 11/10/20
IMPORTANT Because of minimal operations during the holidays and the upcoming Western new year, there won’t be a preview release (known as a “C” release) for the month of December 2020. There will be a monthly security release (known as a “B” release) for December 2020. Normal monthly servicing for both B and C releases will resume in January 2021.

UPDATED 11/10/20
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. To view other notes and messages, see the Windows 10, version 2004 update history home page.NoteFollow @WindowsUpdate to find out when new content is published to the release information dashboard.

Highlights

• Updates to improve security when using input devices such as a mouse, keyboard, or pen.
• Updates to improve security when using Microsoft Office products.
• Updates to improve security when Windows performs basic operations.
• Updates the 2020 DST start date for the Fiji Islands to December 20, 2020.

Improvements and fixes

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Windows 10, version 20H2

This security update includes quality improvements. Key changes include:

• This build includes all the improvements from Windows 10, version 2004.
• No additional issues were documented for this release.

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Windows 10, version 2004

NoteThis release also contains updates for Microsoft HoloLens (OS Build 19041.1128) released November 10, 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:

• Updates the 2020 DST start date for the Fiji Islands to December 20, 2020.
• Addresses a security vulnerability by preventing applications that run as a SYSTEM account from printing to local ports that point to a file. Failing print jobs log error 50, “The request is not supported.” in event ID 372 in the PrintService\Admin event log. To address this issue in the future, make sure your applications or services run as a specific user or service account.
• Security updates to the Microsoft Scripting Engine, Windows Input and Composition, Microsoft Graphics Component, the Windows Wallet Service, Windows Fundamentals, and the Windows Kernel.
  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 new Security Update Guide website.

Windows Update ImprovementsMicrosoft 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.
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.NoteDevices 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.	This issue is resolved in KB4592438.
After installing this update on domain controllers (DCs) and read-only domain controllers (RODCs) in your environment, you might encounter Kerberos authentication and ticket renewal issues. This is caused by an issue in how CVE-2020-17049 was addressed in these updates.For specific symptoms and behaviors related to this issue, please see the Windows release health page for Windows Server, version 20H2 or Windows Server, version 2004 . NoteThis issue only affects Windows Servers, Windows 10 devices and applications in enterprise environments.	This issue is resolved in KB4594440.
When using the Microsoft Japanese Input Method Editor (IME) to enter Kanji characters in an app that automatically allows the input of Furigana characters, you might not get the correct Furigana characters. You might need to enter the Furigana characters manually.Note The affected apps are using theImmGetCompositionString() function.	This issue is resolved in KB5005101.

How to get this update

Before installing this updateMicrosoft 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 (KB4586864) 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 laterClassification: Security Updates File informationFor a list of the files that are provided in this update, download the file information for cumulative update 4586781.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.