dbcve.org
Windows 10 1607Operating system · Microsoft

CVE-2026-50321

HIGH · 7.0 CVSS v3.1 Published 2026-07-14
Fix available
A fix is available. Upgrade to 10.0.14393.9339 / 10.0.17763.9020 or later.
See remediation →
72/100
Remediation priority · Elevated
Zero-click 5 weeks old

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 USB Driver allows an authorized attacker to elevate privileges locally.

In the news

Third-party coverage
Trending covered by 1 outlet this week · latest 1mo ago

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 confidence

A race condition vulnerability exists in a Windows USB driver where improper synchronization of shared resources allows a local authorized attacker to exploit a time-of-check-to-time-of-use (TOCTOU) scenario and elevate privileges to higher authority levels.

MitigationApply the relevant Microsoft security patch or vendor-specific driver update to address the race condition. Validate that USB functionality remains operational after patch deployment.

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:< 10.0.14393.9339
Windows 10 1809Operating system
Affected:< 10.0.17763.9020
Windows 10 21h2Operating system
Affected:< 10.0.19044.7548
Windows 10 22h2Operating system
Affected:< 10.0.19045.7548
Windows 11 24h2Operating system
Affected:< 10.0.26100.8875
Windows 11 25h2Operating system
Affected:< 10.0.26200.8875
Windows 11 26h1Operating system
Affected:< 10.0.28000.2269< 10.0.28000.2525
Windows Server 2012Operating system
Affected:all versions= r2

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 against affected ranges
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to identify your Windows version and build number
    Affected if Build number is less than the thresholds: 14393.9339 (1607), 17763.9020 (1809), 19044.7548 (21h2), 19045.7548 (22h2), 26100.8875 (24h2), 26200.8875 (25h2), 28000.2269/2525 (26h1), or Windows Server 2012/R2 (any version)
  2. Identify USB driver file version
    Locate the USB driver file in System32\drivers folder (commonly usbhub.sys, usbxhci.sys, or ucx010.sys depending on architecture) and check its file version via Properties > Details or 'driverquery /v | findstr usb'
    Affected if Driver file version is older than the patched version corresponding to your Windows build
  3. Confirm USB functionality is in use
    Check if USB driver services are running: 'sc query usbhub' and 'sc query xhci' (or applicable USB controller service) to see if USB stack is active
    Affected if USB drivers/services are loaded and running on the system

System is affected if it runs a Windows version or Server 2012/R2 with build numbers below the patched thresholds AND has USB drivers loaded.

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 10.0.14393.9339 / 10.0.17763.9020 / 10.0.19044.7548 or later
Fixed in 10.0.14393.933910.0.17763.902010.0.19044.7548
Interim mitigation

Apply the relevant Microsoft security patch or vendor-specific driver update to address the race condition. Validate that USB functionality remains operational after patch deployment.

Recommended fix High confidence

Upgrade to the fixed build numbers: 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+), Windows Serv

  1. Open Windows Settings and navigate to Update & Security > Windows Update
  2. Click 'Check for updates' to download and install the latest cumulative update
  3. Verify the installed build number matches or exceeds the fixed version for your Windows release: 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 later
  4. For Windows Server 2012/R2, apply the applicable monthly security update from Microsoft Catalog (kb5002537 or subsequent updates)
  5. Restart the system after updates are installed

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

Fix this in Windows 10 1607 Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,920
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,072.

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-2026-50321 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