October 10, 2023—KB5031354 (OS Build 22621.2428)

For information about Windows update terminology, see the article about the types of Windows updates and the monthly quality update types. For an overview of Windows 11, version 22H2, see its update history page.

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Highlights

This update addresses security issues for your Windows operating system.

Improvements

This security update includes improvements that were a part of update KB5030310 (released September 26, 2023). When you install this KB:

To protect against CVE-2023-44487, you should install the latest Windows update. Based on your use case, you can also set the limit of the RST_STREAMS per minute using the new registry keys in this update.

You can create the DWORD registry values in the table below under the following registry key: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\HTTP\Parameters

These keys are not present by default when you install this KB. You can create them as required to set new values for your environment.

Registry key	Default value	Valid value range	Registry key function
Http2MaxClientResetsPerMinute	400	0–65535	Sets the allowed number of resets (RST_STREAMS) per minute for a connection. When you reach this limit, a GOAWAY message is sent to client for the connection.
Http2MaxClientResetsGoaway	1	0-1	Disables or enables the GOAWAY message to send when you reach the limit. If you set this to 0, the connection ends as soon as you reach the limit.

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

For more information about security vulnerabilities, please refer to the Security Update Guide website and the October 2023 Security Updates.

Windows 11 servicing stack update - 22621.2423

This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. Servicing stack updates (SSU) ensure that you have a robust and reliable servicing stack so that your devices can receive and install Microsoft updates.

Known issues in this update

Applies to	Symptom	Workaround
IT admins	Using the FixedDrivesEncryptionType or SystemDrivesEncryptionType policy settings in the BitLocker configuration service provider (CSP) node in mobile device management (MDM) apps might incorrectly show a 65000 error in the "Require Device Encryption" setting for some devices in your environment. Affected environments are those with the “Enforce drive encryption type on operating system drives” or "Enforce drive encryption on fixed drives" policies set to enabled and selecting either "full encryption" or "used space only". Microsoft Intune is affected by this issue but third-party MDMs might also pe affected. Important This issue is a reporting issue only and does not affect drive encryption or the reporting of other issues on the device, including other BitLocker issues.	This issue is addressed in KB5034204.
All users	Windows devices using more than one (1) monitor might experience issues with desktop icons moving unexpectedly between monitors or other icon alignment issues when attempting to use Copilot in Windows (in preview).	This issue is addressed on the service-side for Windows 11, versions 22H2 and 23H2 on devices with updates released January 9, 2024, or later. Note Managed devices in your environment that have been used or are currently being used in a multimonitor configuration will not yet have Copilot for Windows available.
All users	Third-party wallpaper apps might not work as expected when Copilot in Windows (in preview) is opened. You might see the default wallpaper or the wallpaper set in Windows instead of your custom wallpaper set in the third-party wallpaper app.	This issue is addressed in KB5031455. To prevent users from encountering this issue, Copilot in Windows (in preview) was previously unavailable on devices that have a third-party wallpaper app installed.

Applies to

Symptom

Workaround

IT admins

Using the FixedDrivesEncryptionType or SystemDrivesEncryptionType policy settings in the BitLocker configuration service provider (CSP) node in mobile device management (MDM) apps might incorrectly show a 65000 error in the "Require Device Encryption" setting for some devices in your environment. Affected environments are those with the “Enforce drive encryption type on operating system drives” or "Enforce drive encryption on fixed drives" policies set to enabled and selecting either "full encryption" or "used space only". Microsoft Intune is affected by this issue but third-party MDMs might also pe affected.

Important This issue is a reporting issue only and does not affect drive encryption or the reporting of other issues on the device, including other BitLocker issues.

This issue is addressed in KB5034204.

All users

Windows devices using more than one (1) monitor might experience issues with desktop icons moving unexpectedly between monitors or other icon alignment issues when attempting to use Copilot in Windows (in preview).

This issue is addressed on the service-side for Windows 11, versions 22H2 and 23H2 on devices with updates released January 9, 2024, or later.

Note Managed devices in your environment that have been used or are currently being used in a multimonitor configuration will not yet have Copilot for Windows available.

All users

Third-party wallpaper apps might not work as expected when Copilot in Windows (in preview) is opened. You might see the default wallpaper or the wallpaper set in Windows instead of your custom wallpaper set in the third-party wallpaper app.

This issue is addressed in KB5031455.

To prevent users from encountering this issue, Copilot in Windows (in preview) was previously unavailable on devices that have a third-party wallpaper app installed.

How to get this update

Before installing this update

Microsoft combines the latest servicing stack update (SSU) for your operating system with the latest cumulative update (LCU). For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.

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.
Windows Update for Business	Yes	None. This update will be downloaded and installed automatically from Windows Update in accordance with configured policies.
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 11 Classification: Security Updates

If you want to remove the LCU

To remove the LCU after installing the combined SSU and LCU package, use the DISM/Remove-Package command line option with the LCU package name as the argument. You can find the package name by using this command: DISM /online /get-packages.

Running Windows Update Standalone Installer (wusa.exe) with the /uninstall switch on the combined package will not work because the combined package contains the SSU. You cannot remove the SSU from the system after installation.

File information

For a list of the files that are provided in this update, download the file information for cumulative update 5031354.

For a list of the files that are provided in the servicing stack update, download the file information for the SSU - version 22621.2423.

October 10, 2023—KB5031354 (OS Build 22621.2428)

Highlights

Improvements

Windows 11 servicing stack update - 22621.2423

Known issues in this update

How to get this update

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