Windows 10 Patch Tuesday updates are out now, here's what's new

Today is the second Tuesday of the month, which means it time for Patch Tuesday, the day that all supported versions of Windows receive cumulative updates. This past month, however, has been a busy one for Windows with multiple updates rolling out to all supported versions, with some of them being mandatory ones to address the PrintNightmare vulnerability. Those fixes are rolled into these cumulative updates, for those that haven’t installed them yet. There have also been updates to address gaming performance and PDF issues.

The Redmond firm also released the first Windows 11 Insider Preview build late last month, which has already begun being serviced with cumulative updates. However, there are no new updates being served for the Dev channel today as those releases might – for now – be tied to the usual Wednesday cadence.

As for Windows 10, the three most recent – and fully supported – versions, 2004, 20H2, and 21H1 are receiving KB5004237, bumping the builds up to 19041.1110, 19042.1110, and 19043.1110, respectively. This is because the three versions are built on the same codebase, with the October 2020 Update and May 2021 Update being just enablement packages. The updates bring fixes for issues with certain printer types, such as Zebra printers, that were introduced as part of the PrintNightmare fixes.

As usual, these updates will be offered to users via Windows Update. However, they can also be manually downloaded from the Update Catalog here.

Here are the highlights of the update for the three fully supported Windows versions:

Updates for verifying usernames and passwords.

Updates to improve security when Windows performs basic operations.

Updates an issue that might make printing to certain printers difficult. This issue affects various brands and models, but primarily receipt or label printers that connect using a USB port.

And the complete list of fixes brought by this update are as follows:

Addresses an issue that might make printing to certain printers difficult. This issue affects various brands and models, but primarily receipt or label printers that connect using a USB port.

Removes support for the PerformTicketSignature setting and permanently enables Enforcement mode for CVE-2020-17049. For more information and steps to enable full protection on domain controller servers, see Managing deployment of Kerberos S4U changes for CVE-2020-17049.

Adds Advanced Encryption Standard (AES) encryption protections for CVE-2021-33757. For more information, see KB5004605.

Addresses a vulnerability in which Primary Refresh Tokens are not strongly encrypted. This issue might allow the tokens to be reused until the token expires or is renewed. For more information about this issue, see CVE-2021-33779.

Security updates to Windows Apps, Windows Management, Windows Fundamentals, Windows Authentication, Windows User Account Control (UAC), Operating System Security, Windows Virtualization, Windows Linux, the Windows Kernel, the Microsoft Scripting Engine, the Windows HTML Platforms, the Windows MSHTML Platform, and Windows Graphics.

As is the case with these updates, the firm has listed the known issues in the build that users and admins must be aware of. Here is the complete list:

Symptom	Workaround
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 the ImmGetCompositionString() function.	We are working on a resolution and will provide an update in an upcoming release.
Devices with Windows installations created from custom offline media or custom ISO image might have Microsoft Edge Legacy removed by this update, but not automatically replaced by the new Microsoft Edge. This issue is only encountered when custom offline media or ISO images are created by slipstreaming this update into the image without having first installed the standalone servicing stack update (SSU) released March 29, 2021 or later. Note Devices that connect directly to Windows Update to receive updates are not affected. This includes devices using Windows Update for Business. Any device connecting to Windows Update should always receive the latest versions of the SSU and latest cumulative update (LCU) without any extra steps.	To avoid this issue, be sure to first slipstream the SSU released March 29, 2021 or later into the custom offline media or ISO image before slipstreaming the LCU. To do this with the combined SSU and LCU packages now used for Windows 10, version 20H2 and Windows 10, version 2004, you will need to extract the SSU from the combined package. Use the following steps to extract the using SSU: Extract the cab from the msu via this command line (using the package for KB5000842 as an example): expand Windows10.0-KB5000842-x64.msu /f:Windows10.0-KB5000842-x64.cab Extract the SSU from the previously extracted cab via this command line: expand Windows10.0-KB5000842-x64.cab /f:* You will then have the SSU cab, in this example named SSU-19041.903-x64.cab. Slipstream this file into your offline image first, then the LCU. If you have already encountered this issue by installing the OS using affected custom media, you can mitigate it by directly installing the new Microsoft Edge. If you need to broadly deploy the new Microsoft Edge for business, see Download and deploy Microsoft Edge for business.

Symptom

Workaround

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 the ImmGetCompositionString() function.

We are working on a resolution and will provide an update in an upcoming release.

Devices with Windows installations created from custom offline media or custom ISO image might have Microsoft Edge Legacy removed by this update, but not automatically replaced by the new Microsoft Edge. This issue is only encountered when custom offline media or ISO images are created by slipstreaming this update into the image without having first installed the standalone servicing stack update (SSU) released March 29, 2021 or later.

Note Devices that connect directly to Windows Update to receive updates are not affected. This includes devices using Windows Update for Business. Any device connecting to Windows Update should always receive the latest versions of the SSU and latest cumulative update (LCU) without any extra steps.

To avoid this issue, be sure to first slipstream the SSU released March 29, 2021 or later into the custom offline media or ISO image before slipstreaming the LCU. To do this with the combined SSU and LCU packages now used for Windows 10, version 20H2 and Windows 10, version 2004, you will need to extract the SSU from the combined package. Use the following steps to extract the using SSU:

Extract the cab from the msu via this command line (using the package for KB5000842 as an example): expand Windows10.0-KB5000842-x64.msu /f:Windows10.0-KB5000842-x64.cab
Extract the SSU from the previously extracted cab via this command line: expand Windows10.0-KB5000842-x64.cab /f:*
You will then have the SSU cab, in this example named SSU-19041.903-x64.cab. Slipstream this file into your offline image first, then the LCU.

If you have already encountered this issue by installing the OS using affected custom media, you can mitigate it by directly installing the new Microsoft Edge. If you need to broadly deploy the new Microsoft Edge for business, see Download and deploy Microsoft Edge for business.

However, if you are running older Windows 10 versions such as 1909, 1809, or others, you will also receive updates for the duration that your SKU is supported. Here is a summary of the Windows 10 versions that are still supported, the SKUs they are supported for, and the updates that are rolling out for them.

Version	KB	Build	Download	Support
1909	KB5004245	18363.1679	Update Catalog	Enterprise and Education SKUs
1809	KB5004244	17763.2061	Update Catalog	Long Term Servicing Channel (LTSC)
1607	KB5004238	14393.4530	Update Catalog
1507	KB5004249	10240.19003	Update Catalog

As usual, supported versions will receive mandatory updates via Windows Updates. They should be installed in the background. However, you can also head into Settings > Update & Security > Windows Update to check if these have been downloaded and are awaiting an install. Along with Windows 10, Microsoft is also releasing updates for Windows 8.1 users and those who have opted for Extended Security Updates for Windows 7.