dbcve.org
Windows 10 1809Operating system · Microsoft

CVE-2026-21234

HIGH · 7.0 CVSS v3.1 Published 2026-02-10
Fix available
A fix is available. Upgrade to 10.0.17763.8389 / 10.0.19044.6937 or later.
See remediation →
72/100
Remediation priority · Elevated
Zero-click

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 · unedited
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Connected Devices Platform Service allows an authorized attacker to elevate privileges locally.

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 confidence

A race condition vulnerability exists in the Windows Connected Devices Platform Service where improper synchronization of shared resources allows an authorized local attacker to escalate privileges. The vulnerability stems from concurrent access to a shared resource without proper locking mechanisms.

MitigationApply Microsoft security updates for CVE-2026-21234 when available. If the Connected Devices Platform Service is not required, consider disabling it to reduce attack surface.

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
Windows 10 1809Operating system
Affected:< 10.0.17763.8389
Windows 10 21h2Operating system
Affected:< 10.0.19044.6937
Windows 10 22h2Operating system
Affected:< 10.0.19045.6937
Windows 11 23h2Operating system
Affected:< 10.0.22631.6649
Windows 11 24h2Operating system
Affected:< 10.0.26100.7781
Windows 11 25h2Operating system
Affected:< 10.0.26200.7781
Windows Server 2019Operating system
Affected:< 10.0.17763.8389
Windows Server 2022Operating system
Affected:< 10.0.20348.4711

CVSS 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
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/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 checks

Work through these to decide whether this CVE applies to you.

  1. Check Windows build version
    Open Command Prompt or PowerShell and run 'winver' or 'systeminfo | findstr /B /C:"OS Version"' to obtain the full build number
    Affected if The build number is lower than the threshold for your Windows version (17763.8389 for 1809/Server 2019, 19044.6937 for 21h2, 19045.6937 for 22h2, 22631.6649 for 11 23h2, 26100.7781 for 11 24h2, 26200.7781 for 11 25h2, or 20348.4711 for Server 2022)
  2. Verify Connected Devices Platform Service presence
    Open Services.msc or run 'Get-Service -Name "Cdpsvc"' in PowerShell to check if the Connected Devices Platform Service exists
    Affected if The service is present on the system (service name is Cdpsvc)
  3. Confirm service running status
    Run 'Get-Service -Name "Cdpsvc" | Select-Object Status' in PowerShell or check in Services.msc
    Affected if The service is currently running (Status shows "Running")

You are affected if your Windows build version is lower than the threshold for your specific Windows edition AND the Connected Devices Platform Service is installed and running.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 10.0.17763.8389 / 10.0.19044.6937 / 10.0.19045.6937 or later
Fixed in 10.0.17763.838910.0.19044.693710.0.19045.6937
Interim mitigation

Apply Microsoft security updates for CVE-2026-21234 when available. If the Connected Devices Platform Service is not required, consider disabling it to reduce attack surface.

Recommended fix High confidence

Install the applicable Windows security update for your version (e.g., for Windows 10 22h2 upgrade to build 10.0.19045.6937 or later via Windows Update)

  1. Open Windows Update (Settings > Update & Security > Windows Update)
  2. Click 'Check for updates' to download and install the security update containing the fix for CVE-2026-21234
  3. Restart the system when prompted to complete the installation
  4. Verify the OS build number matches or exceeds the fixed version for your Windows release (1809: 10.0.17763.8389, 21h2: 10.0.19044.6937, 22h2: 10.0.19045.6937, 23h2: 10.0.22631.6649, 24h2: 10.0.26100.7781, 25h2: 10.0.26200.7781, Server 2019: 10.0.17763.8389, Server 2022: 10.0.20348.4711)
Caveat Standard Windows security update—minimal risk; may require restart

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Windows 10 1809 Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,840
Get the upgrade done

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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-21234 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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
  • No spam, self-promotion, credentials, or personal data