CVE-2026-50669
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 Telephony Service allows an authorized attacker to elevate privileges locally.
In the news
Third-party coverage- Microsoft July 2026 Patch Tuesday fixes massive 570 flaws, 3 zero-days
- Microsoft CVE Summary - Bleeping Computer
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 confidenceA race condition vulnerability exists in the Windows Telephory Service where improper synchronization of shared resources allows an authorized local attacker to execute code with elevated privileges. The vulnerability stems from concurrent access to a shared resource without proper locking mechanisms, enabling privilege escalation from a standard user to SYSTEM or equivalent high-privilege context.
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< 10.0.14393.9339< 10.0.17763.9020< 10.0.19044.7548< 10.0.19045.7548< 10.0.26100.8875< 10.0.26200.8875< 10.0.28000.2525all versions= r2CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Check Windows version against affected rangesRun 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to identify your Windows version and build numberAffected if The version is one of: Windows 10 1607 (<10.0.14393.9339), Windows 10 1809 (<10.0.17763.9020), Windows 10 21h2 (<10.0.19044.7548), Windows 10 22h2 (<10.0.19045.7548), Windows 11 24h2 (<10.0.26100.8875), Windows 11 25h2 (<10.0.26200.8875), Windows 11 26h1 (<10.0.28000.2525), or Windows Server 2012/20
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Verify Telephony Service statusRun 'sc query TapiSrv' or 'Get-Service TapiSrv' to check if the Windows Telephony Service is installed and runningAffected if The TapiSrv service exists and is in a running state (the vulnerability applies when this service is available)
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Confirm service startup typeRun 'sc qc TapiSrv' to check the service configuration and startup typeAffected if The service is set to auto-start or manual start, making it exploitable when running
You are affected if you are running a vulnerable Windows version (as listed above) AND the TapiSrv (Telephony) service is present and running on your system.
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 · scoped10.0.14393.933910.0.17763.902010.0.19044.7548
Apply the latest Windows security updates addressing this vulnerability; until patches are available, limit local user privileges and monitor for suspicious processes interacting with the Telephony Service.
Install the latest Windows Security Update for your specific Windows version (minimum: Windows 10 1607 → 10.0.14393.9339, 1809 → 10.0.17763.9020, 21h2 → 10.0.19044.7548, 22h2 → 10.0.19045.7548, 11 24h2 → 10.0.26100.8875, 11 25h2 → 10.0.26200.8875, 11 26h1 → 10.0.28000.2525)
- 1. Open Settings on the Windows machine and navigate to Windows Update, or open the Settings app and check for updates.
- 2. Click 'Check for updates' to download and install the latest security updates for your Windows version.
- 3. After updates are installed, restart the computer when prompted.
- 4. Verify the installed version matches or exceeds the minimum fixed version for your Windows release (e.g., for Windows 10 22h2, verify version is 10.0.19045.7548 or higher).
- 5. For Windows Server 2012 R2 (which has no available security patch per the advisory), consider upgrading to a supported Windows Server version or implementing additional access controls on the system.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation2.0 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 $4,160.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-50669 — 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-2026-50669 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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