IRONSMITHINTEL
HIGHCVSS7.0
|
Actively Exploited
|CISA KEV|CVE-2022-26904|Auth: low — authenticated user|Reboot: required|Manual only

KB5012591: Windows Server Security Update (April 2022)

Microsoft Windows User Profile Service contains an unspecified vulnerability that allows for privilege escalation.

Published Apr 15, 2022 · 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 2022-05-16 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Race Condition (CWE-362) vulnerability in Microsoft Windows. Windows User Profile Service Elevation of Privilege Vulnerability Exploitation requires local access, higher 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 10 1507: v < 10.0.10240.19265; windows 10 1607: v < 10.0.14393.5066; windows 10 1809: v < 10.0.17763.2803; windows 10 1909: v < 10.0.18363.2212; windows 10 20h2: v < 10.0.19042.1645; windows 10 21h1: v < 10.0.19043.1645; windows 10 21h2: v < 10.0.19044.1645; windows 11 21h2: v < 10.0.22000.613; windows 7: -; windows 8.1: -; windows rt 8.1: -; windows server 2008: r2; windows server 2012: -, r2; windows server 2016: v < 10.0.14393.5066; windows server 2019: v < 10.0.17763.2803; windows server 2022: v < 10.0.20348.643; windows server 20h2: v < 10.0.19042.1645
Fixed inKB5012591, KB5012592, KB5012596, KB5012599, KB5012604, KB5012626, KB5012632, KB5012639, KB5012647, KB5012649, KB5012650, KB5012653, KB5012658, KB5012666, KB5012670 (applies to 42 product versions) — build 10.0.10240.19265, 10.0.14393.5066+
Real-world incidentsWhat we've seen

CISA added this CVE to the Known Exploited Vulnerabilities catalog on 2022-04-25 based on evidence of active exploitation in the wild. Federal agencies required to remediate by 2022-05-16.

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 CatalogKB5012591

Manual remediation steps

Apply the Microsoft Security Update

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

Required KB Updates

    1
    KB5012591 — https://support.microsoft.com/help/5012591
    1
    KB5012592 — https://support.microsoft.com/help/5012592
    1
    KB5012596 — https://support.microsoft.com/help/5012596
    1
    KB5012599 — https://support.microsoft.com/help/5012599
    1
    KB5012604 — https://support.microsoft.com/help/5012604
    1
    KB5012626 — https://support.microsoft.com/help/5012626
    1
    KB5012632 — https://support.microsoft.com/help/5012632
    1
    KB5012639 — https://support.microsoft.com/help/5012639
    1
    KB5012647 — https://support.microsoft.com/help/5012647
    1
    KB5012649 — https://support.microsoft.com/help/5012649
    1
    KB5012650 — https://support.microsoft.com/help/5012650
    1
    KB5012653 — https://support.microsoft.com/help/5012653
    1
    KB5012658 — https://support.microsoft.com/help/5012658
    1
    KB5012666 — https://support.microsoft.com/help/5012666
    1
    KB5012670 — https://support.microsoft.com/help/5012670

Supersedes: KB5011485, KB5011487, KB5011491, KB5011493, KB5011495, KB5011497, KB5011503, KB5011534, KB5011535, KB5011552, KB5011564

Affected Products

    1
    Windows 10 Version 1607 for 32-bit Systems
    1
    Windows 10 Version 1607 for x64-based Systems
    1
    Windows 10 Version 1809 for 32-bit Systems
    1
    Windows 10 Version 1809 for ARM64-based Systems
    1
    Windows 10 Version 1809 for x64-based Systems
    1
    Windows 10 Version 1909 for 32-bit Systems
    1
    Windows 10 Version 1909 for ARM64-based Systems
    1
    Windows 10 Version 1909 for x64-based Systems
    1
    Windows 10 Version 20H2 for 32-bit Systems
    1
    Windows 10 Version 20H2 for ARM64-based Systems
    1
    Windows 10 Version 21H1 for 32-bit Systems
    1
    Windows 10 Version 21H1 for ARM64-based Systems
    1
    Windows 10 Version 21H1 for x64-based Systems
    1
    Windows 10 Version 21H2 for 32-bit Systems
    1
    Windows 10 Version 21H2 for ARM64-based Systems
    1
    Windows 10 Version 21H2 for x64-based Systems
    1
    Windows 10 for 32-bit Systems
    1
    Windows 10 for x64-based Systems
    1
    Windows 11 version 21H2 for ARM64-based Systems
    1
    Windows 11 version 21H2 for x64-based Systems
    1
    (…22 more product versions)

Fixed Build Numbers

    1
    10.0.10240.19265
    1
    10.0.14393.5066
    1
    10.0.17763.2803
    1
    10.0.18363.2212
    1
    10.0.19042.1645
    1
    10.0.19043.1645
    1
    10.0.19044.1645
    1
    10.0.20348.643
    1
    10.0.22000.613
    1
    6.0.6003.21446
    1
    (…3 more builds)

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 KB5012591
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 KB5012591 for the affected products in your update management console.

Microsoft Download Center Links

    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5012591
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5012592
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5012596
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5012599
    1
    https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5012604
    1
    (…10 more)

Verification

Confirm the update is installed:

Get-HotFix | Where-Object { $_.HotFixID -in @('KB5012591','KB5012592','KB5012596','KB5012599','KB5012604','KB5012626','KB5012632','KB5012639','KB5012647','KB5012649','KB5012650','KB5012653','KB5012658','KB5012666','KB5012670') }

References

    1
    Microsoft Security Response Center: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2022-26904
    1
    KB article: https://support.microsoft.com/help/5012591
    1
    KB article: https://support.microsoft.com/help/5012592
    1
    KB article: https://support.microsoft.com/help/5012596
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2022-26904
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-26904

Discovery Credit

KLINIX5

PowerShell automationComing soon

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

References

↗ CVE-2022-26904↗ MSRC Advisory↗ NVD↗ KBKB5012591