Windows 10 21h2Operating system · Microsoft

CVE-2026-50423

HIGH · 7.8 CVSS v3.1 Published 2026-07-14
Fix available
A fix is available. Upgrade to 10.0.19044.7548 / 10.0.19045.7548 or later.
See remediation →
80/100
Remediation priority · High
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
Improper access control in Windows Kernel 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 · high confidence

This is a local privilege escalation vulnerability in the Windows Kernel caused by improper access control. An authorized attacker with local access can exploit this kernel-level flaw to elevate their privileges beyond their current authorized permissions, potentially gaining administrator or SYSTEM-level access.

MitigationApply the relevant Microsoft security patch for this kernel vulnerability through standard Windows Update or manual KB deployment, followed by system reboot and verification of privilege separation controls.

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 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 2022Operating system
Affected:< 10.0.20348.5386
Windows Server 2025Operating system
Affected:< 10.0.26100.33158

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
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/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
    Run 'winver' from command prompt or 'systeminfo' and locate the 'OS Build' or 'Build' number in the output
    Affected if The build number is lower than the affected versions: 19044.7548 (Win10 21h2), 19045.7548 (Win10 22h2), 26100.8875 (Win11 24h2), 26200.8875 (Win11 25h2), 28000.2269/28000.2525 (Win11 26h1), 20348.5386 (Server 2022), or 26100.33158 (Server 2025)
  2. Verify Windows edition and release
    Run 'winver' to confirm the exact Windows edition (e.g., Windows 10 21h2, Windows 11 24h2, Windows Server 2022) and match it to the corresponding build number from step 1
    Affected if The edition matches an affected product line and its build falls below the specified threshold for that release
  3. Check CurrentVersion registry key
    Open Registry Editor and navigate to 'HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion', then review the 'CurrentBuild' and 'DisplayVersion' values
    Affected if The CurrentBuild number is less than the affected build threshold for your Windows release
  4. Confirm kernel version (optional verification)
    Run 'kernel32.dll' version check via 'powershell (Get-Item C:\Windows\System32\kernel32.dll).VersionInfo' or check 'systeminfo' for 'Kernel Version'
    Affected if The kernel version corresponds to an unpatched build that falls within the affected ranges

You are affected if your Windows version build number is lower than the threshold listed for your specific Windows release (10/11/Server) and you have not applied the relevant Microsoft security patch for this kernel privilege escalation vulnerability.

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.

From vendor data
Upgrade available Upgrade to 10.0.19044.7548 / 10.0.19045.7548 / 10.0.20348.5386 or later
Fixed in 10.0.19044.754810.0.19045.754810.0.20348.5386
Interim mitigation

Apply the relevant Microsoft security patch for this kernel vulnerability through standard Windows Update or manual KB deployment, followed by system reboot and verification of privilege separation controls.

Fix this in Windows 10 21h2 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

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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-50423 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-50423 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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