CVE-2026-20918
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedConcurrent execution using shared resource with improper synchronization ('race condition') in Windows Management Services allows an authorized attacker to elevate privileges locally.
In the news
Third-party coverage- Microsoft CVE Summary - Bleeping Computer
- Microsoft January 2026 Patch Tuesday fixes 3 zero-days, 114 flaws
Surfaced from public web coverage — external links open in a new tab.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceThis is a race condition vulnerability in Windows Management Services where concurrent execution shares a resource without proper synchronization. An authorized local attacker can exploit this improper synchronization to elevate their privileges from their current user level to higher privileges on the affected Windows system.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 10.0.17763.8276< 10.0.19044.6809< 10.0.19045.6809< 10.0.22631.6491< 10.0.26100.7623< 10.0.26200.7623< 10.0.17763.8276< 10.0.20348.4648CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- High
- Privileges
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check Windows build versionRun `winver` or `systeminfo | findstr /B /C:"OS Version"` or `Get-ComputerInfo | Select-Object WindowsProductName, OsVersion, OsBuildNumber` in PowerShell to retrieve the full build number including the revision (the last 4 digits after the dot).Affected if The build number falls below the fixed version for your specific Windows edition and version.
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Identify Windows product lineRun `systeminfo` or `Get-ComputerInfo` to determine if the system is Windows 10 1809, Windows 10 21h2, Windows 10 22h2, Windows 11 23h2, Windows 11 24h2, Windows 11 25h2, Windows Server 2019, or Windows Server 2022.Affected if The system runs any of the listed affected products and versions.
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Compare against version thresholdsCross-reference the detected build number with the affected version thresholds: Windows 10 1809/Server 2019 requires 10.0.17763.8276 or higher; Windows 10 21h2 requires 10.0.19044.6809 or higher; Windows 10 22h2 requires 10.0.19045.6809 or higher; Windows 11 23h2 requires 10.0.22631.6491 or higher; Windows 11 24h2 requires 10.0.26100.7623 or higher; Windows 11 25h2 requires 10.0.26200.7623 or higher; Windows Server 2022 requires 10.0.20348.4648 or higher.Affected if The installed version is lower than the required version for your specific Windows product.
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Verify Windows Management Services is presentRun `Get-Service -Name "Winmgmt"` or check for the presence of the Windows Management Instrumentation service (WMI) which implements Windows Management Services.Affected if The Windows Management Instrumentation service exists (this is the default state on Windows systems).
You are affected if your Windows version and build number fall below the minimum fixed version listed for your specific Windows product edition.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped10.0.17763.827610.0.19044.680910.0.19045.6809
Apply the Microsoft security update for this vulnerability through Windows Update or manual patch deployment. Limit local administrator access and follow least-privilege principles to reduce the attack surface.
Windows 10 1809: 10.0.17763.8276+ | Windows 10 21h2: 10.0.19044.6809+ | Windows 10 22h2: 10.0.19045.6809+ | Windows 11 23h2: 10.0.22631.6491+ | Windows 11 24h2: 10.0.26100.7623+ | Windows 11 25h2: 10.0.26200.7623+ | Windows Server 2019: 10.0.17763.8276+ | Windows Server 2022: 10.0.20348.4648+
- Open Settings > Update & Security > Windows Update on the affected Windows system
- Click 'Check for updates' and install all available security updates
- For systems without GUI access, run 'wuauclt /detectnow /updatenow' or use WSUS/sccm to deploy updates
- Restart the system after updates are installed
- Verify the installed version matches or exceeds the fixed build number for your Windows version using 'winver' or 'systeminfo'
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-20918 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-20918 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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