KB5041580: Cumulative update for Windows 10, versions 21H2 and 22H2, August 2024. Exploited Windows flaws and critical TCP/IP risk patched

Fixes 43 vulnerabilities, including four being exploited and three rated critical. It also adds Secure Boot protections, but can disrupt Linux dual-boot startup and profile-picture changes.

Does it affect you? Applies to: Devices running Windows 10, version 22H2, and Windows 10 Enterprise LTSC 2021 or Windows 10 IoT Enterprise LTSC 2021, version 21H2.

What changes

Improvements 3 changes

Windows 10, version 22H2

For: Windows 10, version 22H2 devices

This build includes the improvements from the supported Windows 10, version 21H2 editions.¹

Secure Boot Advanced Targeting (SBAT) and Linux Extensible Firmware Interface (EFI)

Windows blocks vulnerable Linux bootloaders from running. The SBAT change is not applied when Windows and Linux dual-booting is detected; older Linux ISO images might not boot after the change.²
Applies SBAT to Windows systems to block vulnerable Linux EFI Shim bootloaders. If an older Linux ISO image does not boot, the source advises contacting the Linux vendor for an updated ISO image.

Servicing stack

The component that installs Windows updates receives quality improvements to help devices receive and install Microsoft updates.³
Includes servicing stack update KB5041579, build 19044.4769.

Removals 2 changes

Lock screen

The “Use my Windows user account” checkbox is no longer available for connecting to Wi-Fi from the lock screen.⁴
The change addresses CVE-2024-38143.

NetJoinLegacyAccountReuse

The NetJoinLegacyAccountReuse registry key is removed.⁵

Fix 1 change

BitLocker

Addresses the issue where a BitLocker recovery screen could appear when you start your device after installing the July 9, 2024 update.⁶

Known issues

Resolved Affects: Organizations and IT administrators Resolved by KB5045594

After installing this update, or subsequent updates, a small subset of Azure Virtual Desktop customers using multi-session hosts (AVD) may experience the following issues: - An extended 10-to-30-minu…

A small subset of Azure Virtual Desktop customers using multi-session hosts might see a 10-to-30-minute black screen after sign-in and single sign-on failures in Office apps. KB5045594 or a later update resolves this when paired with one of the resolution options in KB5048864; both actions are required.⁷

Resolution Fixed in KB5045594

Install KB5045594 (or a later cumulative update) on affected devices. No manual workaround is required after updating.
Resolved Affects: Organizations and IT administrators Resolved by KB5045594

After installing this update, you might experience a black screen when you login to Azure Virtual Desktop (AVD).

A black screen might appear when signing in to Azure Virtual Desktop, and it might persist after disconnecting and reconnecting. KB5045594 or a later update resolves this when paired with one of the resolution options in KB5048864; both actions are required.⁸

Resolution Fixed in KB5045594

Install KB5045594 (or a later cumulative update) on affected devices. No manual workaround is required after updating.
Open Affects: Everyone

After installing this update, you might be unable to [change your user account profile picture](https://support.microsoft.com/en-us/windows/change-your-account-picture-3645cdc7-acab-49d2-76a9-4ce7e5e…

After installing this update, you might be unable to change your user account profile picture. Trying to browse for a picture might produce error 0x80070520. Microsoft says the issue has very limited or no impact for this Windows version.⁹

How to apply the workaround Workaround

Contact Windows support for help if you encounter the issue.⁹
Open Affects: Everyone

After installing this security update, you might face issues with booting Linux if you have enabled the dual-boot setup for Windows and Linux in your device.

Some devices using a Windows/Linux dual-boot setup might fail to start Linux and show an SBAT security-policy error. Customized dual-boot configurations might not be detected, causing the SBAT setting to be applied when it should not be.¹⁰

How to apply the workaround Workaround

Install the September 2024 security update or a later update. On Windows-only systems, set the registry key documented for CVE-2022-2601 and CVE-2023-40547 to ensure the SBAT update is applied; dual-boot systems need no additional steps after installing the September update or later.¹⁰
Step-by-step workaround instructions
2 steps

Show steps Hide steps
Step-by-step procedure
1. Install the September 2024 Windows security update or a later update.
2. On Windows-only systems, set the registry key documented for CVE-2022-2601 and CVE-2023-40547.

Technical details

Data sheet · Security · Downloads · Components Click to collapse or expand

Data sheet

Released: 2024-08-13
Type: Cumulative update

Version	Build	Channel
21H2	19044.4780	General availability
22H2	19045.4780	General availability

Security

43 vulnerabilities fixed

4 exploited 3 critical 40 important

Vulnerability	Severity	CVSS
CVE-2024-38107 Exploited Windows Power Dependency Coordinator Elevation of Privilege Vulnerability	Important	7.8
CVE-2024-38193 Exploited Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability	Important	7.8
CVE-2024-38178 Exploited Scripting Engine Memory Corruption Vulnerability	Important	7.5
CVE-2024-38106 Exploited Windows Kernel Elevation of Privilege Vulnerability	Important	7.0
CVE-2024-38063 Windows TCP/IP Remote Code Execution Vulnerability	Critical	9.8
CVE-2024-38140 Windows Reliable Multicast Transport Driver (RMCAST) Remote Code Execution Vulnerability	Critical	9.8
CVE-2022-3775 Redhat: CVE-2022-3775 grub2 - Heap based out-of-bounds write when rendering certain Unicode sequences	Critical	7.1
CVE-2024-38199 Windows Line Printer Daemon (LPD) Service Remote Code Execution Vulnerability	Important	9.8
CVE-2024-21302 Windows Secure Kernel Mode Elevation of Privilege Vulnerability	Important	6.7

The table lists the 9 exploited, publicly disclosed or critical vulnerabilities. See all 43 vulnerabilities →

Sources

Microsoft Support: KB5041580

Updated Oct 27, 2026

Cited passages from Microsoft's official notes (10)

1. This build includes all the improvements from the supported Windows 10, version 21H2 editions. support.microsoft.com
2. This update applies SBAT to systems that run Windows. This stops vulnerable Linux EFI (Shim bootloaders) from running. support.microsoft.com
3. This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. support.microsoft.com
4. This update addresses CVE-2024-38143. Because of this, the “Use my Windows user account” checkbox is not available on the lock screen to connect to Wi-Fi. support.microsoft.com
5. [NetJoinLegacyAccountReuse] This update removes this registry key. support.microsoft.com
6. A BitLocker recovery screen shows when you start up your device. This occurs after you install the July 9, 2024, update. support.microsoft.com
7. Note that you need to perform both actions to resolve the issue. support.microsoft.com
8. This issue is resolved by installing the Windows updates released October 22, 2024 (KB5045594) or later updates and by applying one of the options mentioned in the Resolution section in KB5048864. support.microsoft.com
9. If you encounter this issue on your device, please contact Windows support for help support.microsoft.com
10. The September 2024 Windows security update (KB5043064) and later updates do not contain the settings that caused this issue. support.microsoft.com

Checked automatically: 7 of 8 checks passed, 10 quoted passages · compared with Microsoft's page on Nov 8, 2026

Quotes found in the official pages: passed
Numbers found in the sources: passed
Vulnerabilities from the dossier only: passed
Links to allowed domains only: passed
Every official change covered: passed
Readable plain text: passed
Changes confirmed by the file list: passed
Sources agree: not passed

A second AI read the text against the sources: correctness 5/5, clarity 4/5, completeness 4/5. How we work

Published by The Update Bureau. Written with AI from Microsoft's own documents, checked by rules and a second AI. How we work · Report a mistake