dbcve.org
Windows 10 1607Operating system · Microsoft

CVE-2026-42912

HIGH · 7.0 CVSS v3.1 Published 2026-06-09
Fix available
A fix is available. Upgrade to 10.0.14393.9234 / 10.0.17763.8880 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 Telephony 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 Windows Telephony Service where concurrent access to shared resources lacks proper synchronization. An authorized attacker with local access can exploit this timing vulnerability to elevate their privileges from a standard user to higher-level system permissions.

MitigationApply the Microsoft security update for CVE-2026-42912 to all affected Windows systems. Prioritize endpoints where users have local access or where Telephony Service is running.

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 1607Operating system
Affected:< 10.0.14393.9234
Windows 10 1809Operating system
Affected:< 10.0.17763.8880
Windows 10 21h2Operating system
Affected:< 10.0.19044.7417
Windows 10 22h2Operating system
Affected:< 10.0.19045.7417
Windows 11 23h2Operating system
Affected:< 10.0.22631.7219
Windows 11 24h2Operating system
Affected:< 10.0.26100.8655
Windows 11 25h2Operating system
Affected:< 10.0.26200.8655
Windows 11 26h1Operating system
Affected:< 10.0.28000.2269

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 version
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to identify your Windows version and build number
    Affected if The build number is lower than any of these: 14393.9234 (Win10 1607), 17763.8880 (Win10 1809), 19044.7417 (Win10 21h2), 19045.7417 (Win10 22h2), 22631.7219 (Win11 23h2), 26100.8655 (Win11 24h2), 26200.8655 (Win11 25h2), 28000.2269 (Win11 26h1)
  2. Verify Telephony Service presence
    Run 'Get-Service TphSvc' or 'sc query TphSvc' to check if the Windows Telephony Service is present on the system
    Affected if The service exists and is running - the vulnerability requires this service to be available for privilege escalation
  3. Check for installed security updates
    Run 'Get-HotFix | Where-Object {$_.Description -eq "Security Update"} | Sort-Object InstalledOn -Descending | Select-Object -First 10' to list recently installed security updates, or check Windows Update history for the specific CVE patch
    Affected if The relevant security update for CVE-2026-42912 is NOT installed - no corresponding KB article or security patch found in the update history

You are affected if your Windows build number falls below the affected thresholds AND the Telephony Service is present on your system AND the corresponding security update is not installed.

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 10.0.14393.9234 / 10.0.17763.8880 / 10.0.19044.7417 or later
Fixed in 10.0.14393.923410.0.17763.888010.0.19044.7417
Interim mitigation

Apply the Microsoft security update for CVE-2026-42912 to all affected Windows systems. Prioritize endpoints where users have local access or where Telephony Service is running.

Recommended fix High confidence

Install the latest Windows security updates from Windows Update that address CVE-2026-42912

  1. Open Windows Settings and navigate to Windows Update
  2. Click 'Check for updates' to download and install the latest security updates
  3. Ensure the update includes the patch for CVE-2026-42912 (Windows Telephony Service privilege escalation)
  4. Restart the system after updates are installed
  5. Verify the installed Windows version matches or exceeds the fixed build number for your release: Windows 10 1607: 10.0.14393.9234, Windows 10 1809: 10.0.17763.8880, Windows 10 21h2: 10.0.19044.7417, Windows 10 22h2: 10.0.19045.7417, Windows 11 23h2: 10.0.22631.7219, Windows 11 24h2: 10.0.26100.8655, Windows 11 25h2: 10.0.26200.8655, Windows 11 26h1: 10.0.28000.2269
Caveat Standard Windows update risks: update may require restart, ensure backups of critical data before applying

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

Fix this in Windows 10 1607 Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

Scan for this in your stack

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dbcve dependency scanner

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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-2026-42912 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