Skip to the content
The Update Bureau
Windows 11 23H2 Windows 11 23H2 Security update
Patch Tuesday Zero-day

KB5034765

KB5034765: Cumulative update for Windows 11, version 23H2, February 2024. Exploited kernel flaw patched; taskbar layout changes

In short

Addresses 41 vulnerabilities, including three exploited flaws, and changes the taskbar layout. It also addresses slow Narrator announcements and Explorer hangs during shutdown or restart.

Does it affect you? Applies to: Devices running Windows 11, version 22H2 or 23H2. The 22H2 servicing-date changes differ by edition.

Build
22631.3155
Security
41 fixed · 2 critical · 3 exploited
Restart
Required

What changes

Improvements 3 changes

Taskbar

Gradual rollout Verified in package
  • Show desktop is off by default at the rightmost corner of the taskbar. You can turn it back on in Taskbar settings.1
    Go to Settings > Personalization > Taskbar, or right-click the taskbar and choose Taskbar settings.

Device metadata

For: Devices downloading metadata from WMIS

  • Device metadata downloads over HTTPS are more secure.2
    Applies to downloads from Windows Metadata and Internet Services (WMIS).

Servicing stack

  • The component that installs Windows updates receives quality improvements.3
    Includes servicing stack update versions 22621.3073 and 22631.3073.

Fixes 2 changes

Narrator

For: People using Narrator with Natural Voices

  • Narrator announcements with Natural Voices are less slow.4
    Addresses slow Narrator announcements when using Natural Voices.

File Explorer

  • On PCs with a controller accessory attached, Explorer is less likely to stop responding during restart or shutdown.4
    Addresses an issue affecting explorer.exe when restarting or shutting down a PC with a controller accessory attached.

New feature 1 change

Taskbar

Gradual rollout
  • The Copilot icon appears on the right side of the taskbar’s system tray.1

Known issues

  1. Resolved Affects: Everyone Resolved by KB5035853

    Windows 11 devices attempting to install the February 2024 security update, released February 13, 2024 (KB5034765), might face issues during the update process.

    The update installation might fail when the download reaches 96%, and the device might roll back to its previous update. The issue might appear in Event Viewer with error code 0x800F0922. KB5035853 addresses it.5

    Resolution Fixed in KB5035853

    Install KB5035853 (or a later cumulative update) on affected devices. No manual workaround is required after updating.

Technical details

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

Data sheet

Released
2024-02-13
Classification
Security Updates
Type
Cumulative update
Restart
Required
Replaces
KB5034204, KB5034123
Replaced by
KB5035853
VersionBuildChannel
23H2 22631.3155 General availability

Security

41 vulnerabilities fixed
3 exploited 2 critical 38 important 1 moderate
VulnerabilitySeverityCVSS
CVE-2024-21412 Exploited
Internet Shortcut Files Security Feature Bypass Vulnerability
 Important 8.1
CVE-2024-21338 Exploited
Windows Kernel Elevation of Privilege Vulnerability
 Important 7.8
CVE-2024-21351 Exploited
Windows SmartScreen Security Feature Bypass Vulnerability
 Moderate 7.6
CVE-2024-21357
Windows Pragmatic General Multicast (PGM) Remote Code Execution Vulnerability
 Critical 8.1
CVE-2024-20684
Windows Hyper-V Denial of Service Vulnerability
 Critical 6.5

The table lists the 5 exploited, publicly disclosed or critical vulnerabilities. See all 41 vulnerabilities →

Updated components

1,962 files changed since the previous update for the same versions.

Top changed componentsFiles
Settings46
Graphics and display36
Windows Update32
File Explorer and shell28
Remote Desktop24
Networking18
Security and sign-in18
Audio16
Search14
Hyper-V and virtualization13
Bluetooth10
Secure Boot9

Verified in package: changed files confirm Taskbar.

Sources

Updated
Cited passages from Microsoft's official notes (5)
  1. 1. New! The Copilot in Windows icon now appears on the right side of the system tray on the taskbar. Also, the display of Show desktop at the rightmost corner of the taskbar will be off by default. support.microsoft.com
  2. 2. This update addresses an issue that affects the download of device metadata. Downloads from the Windows Metadata and Internet Services (WMIS) over HTTPS are now more secure. support.microsoft.com
  3. 3. This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. support.microsoft.com
  4. 4. This update addresses an issue that affects Narrator announcements. They are slow when you use Natural Voices. This update addresses an issue that affects explorer.exe. It might stop responding. support.microsoft.com
  5. 5. The installation might fail when the update's download reaches 96% of completion, and the device might roll back to the previous update installed. support.microsoft.com
Checked automatically: 8 of 8 checks passed, 5 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 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