Skip to the content
The Update Bureau
Windows 11 24H2 Windows 11 24H2 Security update
Patch Tuesday Zero-day

KB5041571

KB5041571: Cumulative update for Windows 11, version 24H2, August 2024. TCP/IP remote-code flaw patched; Roblox blocked on Arm

In short

Fixes 45 vulnerabilities, including four being exploited and a critical TCP/IP flaw. Arm users cannot download or play Roblox from the Microsoft Store, but can get it from Roblox.com.

Does it affect you? Applies to: Windows 11, version 24H2, targeting Copilot+ PCs and devices that previously used Windows Insider 24H2 builds.

Build
26100.1457
Security
45 fixed · 3 critical · 4 exploited
Restart
Required
Review notes Additional details from the official release notes (1) Read note
  • This page On Arm devices, Roblox cannot be downloaded and played through the Microsoft Store. Players can download it directly from Roblox.com.

The official sources are linked at the end of the page.

What changes

Improvements 4 changes

Lock screen

  • The “Use my Windows user account” checkbox is no longer available when connecting to Wi-Fi from the lock screen.1
    Addresses CVE-2024-38143.

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

For: Windows systems that do not dual-boot Linux

  • Windows systems block vulnerable Linux EFI bootloaders. This SBAT update does not apply to systems that dual-boot Windows and Linux. Older Linux ISO images might not boot after the update; if that happens, get an updated ISO from your Linux vendor.2
    Applies SBAT to Windows systems to stop vulnerable Linux EFI Shim bootloaders from running.

Domain Name System (DNS)

  • DNS server security is hardened. Outdated domain configurations might cause SERVFAIL errors or timeouts.3
    Addresses CVE-2024-37968.

Servicing stack

  • The component that installs Windows updates receives quality improvements.4
    Includes servicing stack update KB5041575, version 26100.1440.

Removal 1 change

NetJoinLegacyAccountReuse

  • The NetJoinLegacyAccountReuse registry key is removed.5
    See KB5020276 for details about domain join hardening changes.

Known issues

  1. Open Affects: Everyone

    We’re aware of an issue where players on Arm devices are unable to download and play Roblox via the Microsoft Store on Windows.

    Players on Arm devices are unable to download and play Roblox via the Microsoft Store on Windows.6

    How to apply the workaround Workaround

    Download Roblox directly from Roblox.com.6

Technical details

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

Data sheet

Released
2024-08-13
Classification
Security Updates
Type
Cumulative update
Restart
Required
Replaces
KB5040529, KB5040435, KB5039304, KB5039239
Replaced by
KB5041865
VersionBuildChannel
24H2 26100.1457 General availability

Security

45 vulnerabilities fixed
4 exploited 3 critical 41 important 1 not rated
VulnerabilitySeverityCVSS
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

The table lists the 8 exploited, publicly disclosed or critical vulnerabilities. See all 45 vulnerabilities →

Sources

Updated
Cited passages from Microsoft's official notes (6)
  1. 1. [Lock screen] 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
  2. 2. [Secure Boot Advanced Targeting (SBAT) and Linux Extensible Firmware Interface (EFI)] This update applies SBAT to systems that run Windows. This stops vulnerable Linux EFI (Shim bootloaders) from running. support.microsoft.com
  3. 3. [Domain Name System (DNS)] This update hardens DNS server security to address CVE-2024-37968. If the configurations of your domains are not up to date, you might get the SERVFAIL error or time out. support.microsoft.com
  4. 4. This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. support.microsoft.com
  5. 5. [NetJoinLegacyAccountReuse] This update removes this registry key. For more information refer to KB5020276—Netjoin: Domain join hardening changes. support.microsoft.com
  6. 6. We’re aware of an issue where players on Arm devices are unable to download and play Roblox via the Microsoft Store on Windows. Players on Arm devices can play Roblox by downloading the title directly from www.Roblox.com. support.microsoft.com
Checked automatically: 7 of 8 checks passed, 6 quoted passages · compared with Microsoft's page on Oct 20, 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 4/5, clarity 4/5, completeness 5/5. 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