202310 Cumulative Update For Windows 11 For X64based Systems Kb5031358 Exclusive ^hot^ May 2026

KB5031358 is a significant security update for Windows 11, released on October 10, 2023. Specifically targeting Windows 11 version 21H2, this update advanced the OS build to 22000.2538. It is primarily recognized as the final "Patch Tuesday" update for the original release of Windows 11, marking its formal end of support. Key Features and Security Enhancements

This exclusive article provides an exhaustive technical breakdown, hands-on performance analysis, security advisory details, installation troubleshooting, and the hidden "exclusive" changes that Microsoft’s release notes barely mentioned. KB5031358 is a significant security update for Windows

update, released on October 10, 2023, for Windows 11 version 21H2 You must have the September 2023 servicing stack

5. Installation & System Requirements

5.1 Prerequisites

You must have the September 2023 servicing stack update (SSU) (KB5031539) installed automatically via Windows Update. Manual installers require the SSU first.
Windows 11 version 22H2 build must be 22621.1 or higher.

Try standalone install from Update Catalog (run elevated).

Check CBS and WindowsUpdate logs for error codes; search MS Docs/Answers for specific codes (e.g., 0x800f0988).

If BitLocker CSP reporting 65000 in Intune, plan to install the later fix (KB5034121).

Issue 2: Slow Copying of Large Files Over SMB

Affects: x64 systems with SMB compression enabled.
Symptoms: Copying a 10GB file over a 10Gbps network drops from 800 MB/s to 40 MB/s.
Workaround: Disable SMB compression via Set-SmbClientConfiguration -EnableCompression $false in PowerShell.

Reliability Enhancements: Microsoft focuses on making the operating system more reliable by fixing issues related to hardware compatibility, driver updates, and system file integrity. Try standalone install from Update Catalog (run elevated)

Check OS Build: Run winver. You should see Version 22H2 (OS Build 22621.2428).
Verify KB installation: In PowerShell:
```
Get-HotFix | Where-Object $_.HotFixID -eq "KB5031358"
```
Expected output: InstalledOn: 10/11/2023 12:00:00 AM (or your local date).
Check x64 architecture: Run systeminfo | findstr /C:"System Type". Must return: System Type: x64-based PC.