CVE-2026-20874
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 coverageSurfaced 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 confidenceA race condition vulnerability exists in Windows Management Services where concurrent execution of operations on shared resources lacks proper synchronization. An authorized local attacker can exploit this timing vulnerability to elevate their privileges to higher levels 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 installed Windows versionRun 'winver' from the Start menu or execute 'systeminfo' in Command Prompt and locate the 'OS Version' field. Compare the displayed build number against the affected version ranges.Affected if The installed build number falls below the minimum fixed version for your Windows release (e.g., below 10.0.17763.8276 for Windows 10 1809/Server 2019, below 10.0.19044.6809 for Windows 10 21h2, etc.).
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Verify Windows Management Services presenceOpen Services (services.msc) and locate 'Windows Management Service' or 'Windows Management Instrumentation' (WMI) service. Confirm the service exists and note its status (Running/Stopped).Affected if The Windows Management Service or WMI service is present on the system, as this is the component containing the race condition vulnerability.
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Check Windows Management Instrumentation service statusRun 'sc query winmgmt' in Command Prompt or check the service status in Services.msc under 'Windows Management Instrumentation'.Affected if The WMI service is in a Running or Started state, meaning the vulnerable code path could be exercised.
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Identify exact OS build for precise version matchingExecute 'ver' in Command Prompt or retrieve the build from 'HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion' registry key (CurrentBuild and DisplayVersion values).Affected if The exact build number obtained is lower than the corresponding threshold in the affected products list for your specific Windows release.
Your system is affected if it runs any of the listed Windows versions AND has Windows Management Services/WMI available, with the installed build number falling below the specified threshold for that release.
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 CVE-2026-20874 when released. In the interim, limit local user privileges to the minimum required and monitor for suspicious process activity.
Upgrade to the build number >= your respective fixed version: 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: 10.0.17
- Check current Windows version by running 'winver' or 'systeminfo' in Command Prompt
- Identify the specific Windows release (1809, 21h2, 22h2, 23h2, 24h2, 25h2, Server 2019, or Server 2022)
- Open Windows Update by going to Settings > Update & Security > Windows Update
- Click 'Check for updates' to download and install the latest security updates
- Alternatively, manually download the security update for your specific Windows version from the Microsoft Update Catalog (search for the KB article associated with this CVE)
- Restart the system after the update is installed
- Verify the update was successful by checking the installed updates list or running 'winver' to confirm the build number matches the fixed version
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,096.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-20874 — 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-2026-20874 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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- Version or environment caveats, and links to real fixes
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