IRONSMITHINTEL
HIGHCVSS7.8
|
Actively Exploited
|CISA KEV|CVE-2024-38080|Auth: low — authenticated user|Reboot: required|Manual only

KB5040431: Windows Server Security Update (July 2024)

Microsoft Windows Hyper-V contains a privilege escalation vulnerability that allows a local attacker with user permissions to gain SYSTEM privileges.

Published Jul 9, 2024 · Updated May 16, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A local attacker, with a low-privilege account, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. Federal agencies are required to remediate by 2024-07-30 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Integer Overflow (CWE-190) vulnerability in Microsoft Windows. Windows Hyper-V Elevation of Privilege Vulnerability Exploitation requires local access, low attack complexity, a low-privilege authenticated account, and no user interaction required.

Am I affected?Quick check

Probably yes if any of these apply:

●Windows Administrators
●Systems Engineers
●IT Security
●Running windows 11 21h2: v < 10.0.22000.3079; windows 11 22h2: v < 10.0.22621.3880; windows 11 23h2: v < 10.0.22631.3880; windows server 2022: v < 10.0.20348.2582; windows server 2022 23h2: v < 10.0.25398.1009
Fixed inKB5040431, KB5040437, KB5040438, KB5040442 (applies to 9 product versions) — build 10.0.20348.2582, 10.0.22000.3079+
Real-world incidentsWhat we've seen

CISA added this CVE to the Known Exploited Vulnerabilities catalog on 2024-07-09 based on evidence of active exploitation in the wild. Federal agencies required to remediate by 2024-07-30.

How to patch

Manual download

For air-gapped servers or out-of-band deployment. Microsoft Update Catalog returns every OS-version variant of this update.

↗ Microsoft Update CatalogKB5040431

Manual remediation steps

Apply the Microsoft Security Update

Microsoft has released an official security update that fixes this vulnerability.

Required KB Updates

    1
    KB5040431 — https://support.microsoft.com/help/5040431
    1
    KB5040437 — https://support.microsoft.com/help/5040437
    1
    KB5040438 — https://support.microsoft.com/help/5040438
    1
    KB5040442 — https://support.microsoft.com/help/5040442

Supersedes: KB5039212, KB5039213, KB5039227, KB5039236

Affected Products

    1
    Windows 11 Version 22H2 for ARM64-based Systems
    1
    Windows 11 Version 22H2 for x64-based Systems
    1
    Windows 11 Version 23H2 for ARM64-based Systems
    1
    Windows 11 Version 23H2 for x64-based Systems
    1
    Windows 11 version 21H2 for ARM64-based Systems
    1
    Windows 11 version 21H2 for x64-based Systems
    1
    Windows Server 2022
    1
    Windows Server 2022 (Server Core installation)
    1
    Windows Server 2022, 23H2 Edition (Server Core installation)

Fixed Build Numbers

    1
    10.0.20348.2582
    1
    10.0.22000.3079
    1
    10.0.22621.3880
    1
    10.0.22631.3880
    1
    10.0.25398.1009

Installation Methods

Windows Update (recommended)

1
Settings → Windows Update → Check for updates
2
The security update is offered if your system is in scope
3
Restart when prompted — a reboot IS required to complete the install

Microsoft Update Catalog (manual download)

1
Open https://catalog.update.microsoft.com
2
Search for KB5040431
3
Download the package matching your OS architecture and Windows build
4
Run the .msu installer with administrator privileges
5
Restart when prompted

WSUS / SCCM / Intune

Approve KB5040431 for the affected products in your update management console.

Microsoft Download Center Links

    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5040431
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5040437
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5040438
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5040442

Verification

Confirm the update is installed:

Get-HotFix | Where-Object { $_.HotFixID -in @('KB5040431','KB5040437','KB5040438','KB5040442') }

References

    1
    Microsoft Security Response Center: https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2024-38080
    1
    KB article: https://support.microsoft.com/help/5040431
    1
    KB article: https://support.microsoft.com/help/5040437
    1
    KB article: https://support.microsoft.com/help/5040438
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2024-38080
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-38080

Discovery Credit

Anonymous

PowerShell automationComing soon

No tested PowerShell script for this entry yet. We’re prioritising automation based on user demand.

References

↗ CVE-2024-38080↗ MSRC Advisory↗ NVD↗ KBKB5040431