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Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update
Patch Tuesday Zero-day

KB5051974

KB5051974: Cumulative update for Windows 10, versions 21H2 and 22H2, February 2025. Exploited Storage and WinSock flaws put Windows at risk

In short

Attackers are exploiting flaws in Windows Storage and the WinSock ancillary function driver. An LDAP flaw also allows remote code execution; USB printer and other known issues are listed.

Does it affect you? Applies to: This update is for Windows 10 version 22H2 and Windows 10 Enterprise LTSC 2021 and IoT Enterprise LTSC 2021, version 21H2.

Builds
19044.5487 · 19045.5487
Security
32 fixed · 1 critical · 2 exploited

What changes

Improvements 3 changes

Windows 10, version 22H2

For: Windows 10 version 22H2 devices

  • Version 22H2 includes all improvements from supported version 21H2 editions.1

Windows 10, version 21H2

For: Windows 10 Enterprise LTSC 2021 and IoT Enterprise LTSC 2021 devices

  • Windows gets miscellaneous security improvements to internal features.1
    Applies to Windows 10 Enterprise LTSC 2021 and Windows 10 IoT Enterprise LTSC 2021.

Servicing stack

For: Windows 10 devices

  • The component that installs Windows updates gets quality improvements.2
    Servicing stack update KB5050111, build 19044.5425 and 19045.5425.

Known issues

  1. Open Affects: Organizations and IT administrators

    Citrix

    Devices with Citrix Session Recording Agent version 2411 might fail to finish installing the January 2025 security update and undo its changes. Home users are not expected to be affected.3

    How to apply the workaround Workaround

    Upgrade Citrix Session Recording Agent to version 2503 or newer.3

  2. Open Affects: Everyone

    System Guard Runtime Monitor Broker service

    Event Viewer might show an error for the System Guard Runtime Monitor Broker service. The error is silent and should not affect performance, features, or device security.4

    How to apply the workaround Workaround

    The page says KB5055612 addresses this issue.4

  3. Open Affects: Organizations and IT administrators

    USB Printer Issue

    Some USB-connected dual-mode printers might print random text and data, often starting with “POST /ipp/print HTTP/1.1”. This is more likely when the printer is turned on or reconnected.5

    How to apply the workaround Workaround

    The page says KB5053643 addresses this issue.5

  4. Open Affects: Everyone

    Open Secure Shell service

    On some devices, the Open Secure Shell service might fail to start, blocking SSH connections. Microsoft says it is investigating whether Home or Pro devices are affected.6

    How to apply the workaround Workaround

    The page says KB5052077 addresses this issue.6

Technical details

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

Data sheet

Released
2025-02-11
Type
Cumulative update
VersionBuildChannel
21H2 19044.5487 General availability
22H2 19045.5487 General availability

Security

32 vulnerabilities fixed
2 exploited 1 critical 31 important
VulnerabilitySeverityCVSS
CVE-2025-21418 Exploited
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
 Important 7.8
CVE-2025-21391 Exploited
Windows Storage Elevation of Privilege Vulnerability
 Important 7.1
CVE-2025-21376
Windows Lightweight Directory Access Protocol (LDAP) Remote Code Execution Vulnerability
 Critical 8.1
CVE-2025-21377
NTLM Hash Disclosure Spoofing Vulnerability
 Important 6.5

The table lists the 4 exploited, publicly disclosed or critical vulnerabilities. See all 32 vulnerabilities →

Sources

Updated
Cited passages from Microsoft's official notes (6)
  1. 1. This build includes all the improvements from the supported Windows 10, version 21H2 editions. support.microsoft.com
  2. 2. This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. support.microsoft.com
  3. 3. The issue has been resolved in Citrix Session Recording Agent version 2503, released on April 28, 2025, and newer versions. support.microsoft.com
  4. 4. This issue is addressed in KB5055612. support.microsoft.com
  5. 5. This issue is addressed in KB5053643. support.microsoft.com
  6. 6. Following the installation of the October 2024 security update, some customers report that the OpenSSH (Open Secure Shell) service fails to start, preventing SSH connections. support.microsoft.com
Checked automatically: 7 of 8 checks passed, 6 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