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Windows 11 23H2 Windows 11 23H2 Security update
Patch Tuesday

KB5035853

KB5035853: Cumulative update for Windows 11, version 23H2, March 2024. Critical Hyper-V flaws addressed; February update hang resolved

In short

Addresses two critical Hyper-V vulnerabilities and an installation problem that could leave February updates stuck at 96%.

Does it affect you? Applies to: Devices running Windows 11, version 22H2 or 23H2.

Build
22631.3296
Security
38 fixed · 2 critical
Restart
Required

What changes

Improvements 2 changes

Windows 11, version 23H2

  • This build includes the improvements released for Windows 11, version 22H2.1

Servicing stack

  • The servicing stack, which installs Windows updates, receives quality improvements.2
    Includes servicing stack update versions 22621.3294 and 22631.3294.

Fix 1 change

Windows Update

Verified in package

For: devices installing the February 2024 security or preview updates

  • Addresses an issue that could stop the February 2024 security and preview updates from installing, leaving a device stuck at 96% with error 0x800F0922.3

Technical details

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

Data sheet

Released
2024-03-12
Classification
Security Updates
Type
Cumulative update
Restart
Required
Replaces
KB5034848, KB5034765, KB5034204, KB5034123
Replaced by
KB5036893
VersionBuildChannel
23H2 22631.3296 General availability

Security

38 vulnerabilities fixed
2 critical 36 important
VulnerabilitySeverityCVSS
CVE-2024-21407
Windows Hyper-V Remote Code Execution Vulnerability
 Critical 8.1
CVE-2024-21408
Windows Hyper-V Denial of Service Vulnerability
 Critical 5.5

The table lists the 2 exploited, publicly disclosed or critical vulnerabilities. See all 38 vulnerabilities →

Updated components

571 files changed since the previous update for the same versions.

Top changed componentsFiles
Hyper-V and virtualization21
Secure Boot10
Bluetooth8
File Explorer and shell8
Graphics and display7
Kernel5
Storage and file systems5
Security and sign-in4
Windows Update2
Remote Desktop1

Verified in package: changed files confirm Windows Update.

Sources

Updated
Cited passages from Microsoft's official notes (3)
  1. 1. This build includes all the improvements in Windows 11, version 22H2. 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. This update addresses a known issue that might affect the February 2024 security and preview updates. They might not install, and your device might stop responding at 96%. The error code is "0x800F0922.” support.microsoft.com
Checked automatically: 8 of 8 checks passed, 3 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: passed

A second AI read the text against the sources: correctness 5/5, clarity 5/5, 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