dbcve.org
Windows 10 21h2Operating system · Microsoft

CVE-2026-50459

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
Use after free in Windows Kernel allows an unauthorized 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 use-after-free vulnerability exists in the Windows Kernel where memory is freed but still accessed, allowing a local attacker to manipulate kernel memory and elevate privileges to SYSTEM level.

MitigationApply Microsoft security updates for Windows Kernel when available; prioritize patching systems with direct local access given the privilege elevation vector.

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. Identify Windows version and build number
    Open Command Prompt or PowerShell and run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"'. Alternatively, run 'ver' in cmd to get the build number.
    Affected if Unable to determine version or build number for comparison
  2. Confirm Windows edition or product type
    Run 'systeminfo' and look for the OS Name field (e.g., 'Microsoft Windows 10 Pro', 'Microsoft Windows Server 2022') to identify if it is a desktop or server edition and which release (21h2, 22h2, 24h2, etc.).
    Affected if Uncertain which version family applies for comparison
  3. Compare build number against vulnerability ranges
    Match your identified Windows version and build number against the affected ranges: Windows 10 21h2 requires build < 10.0.19044.7548, Windows 10 22h2 requires < 10.0.19045.7548, Windows 11 24h2 requires < 10.0.26100.8875, Windows 11 25h2 requires < 10.0.26200.8875, Windows 11 26h1 requires < 10.0.28000.2269 or < 10.0.28000.2525, Server 2022 requires < 10.0.20348.5386, Server 2025 requires < 10.0.26100.33158.
    Affected if Installed build number falls below the specified threshold for that Windows product line
  4. Verify if security update is installed
    Open Settings > Windows Update > Update History, or run 'wmic qfe list' in PowerShell, and look for a Windows Kernel security update installed after the vulnerability disclosure date with a KB number matching the relevant security patch.
    Affected if No corresponding Windows Kernel security update found in update history

The system is affected if it runs any of the listed Windows versions and its installed build number is lower than the corresponding fixed version for that product line.

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 10.0.19044.7548 / 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 Microsoft security updates for Windows Kernel when available; prioritize patching systems with direct local access given the privilege elevation vector.

Recommended fix High confidence

Apply the Microsoft security update for CVE-2026-50459 from Windows Update or WSUS/Windows Server Update Services

  1. Open Settings > Update & Security > Windows Update on the affected Windows system
  2. Click 'Check for updates' to retrieve the latest security patches from Microsoft Update
  3. Locate and install the security update that addresses CVE-2026-50459 (typically released as part of a monthly Windows Security update)
  4. Restart the system when prompted to complete the installation
  5. Verify the installed version matches or exceeds the fixed version for your product: Windows 10 21h2 should be 10.0.19044.7548 or higher; Windows 10 22h2 should be 10.0.19045.7548 or higher; Windows 11 24h2 should be 10.0.26100.8875 or higher; Windows 11 25h2 should be 10.0.26200.8875 or higher; Windows 11 26h1 should be 10.0.28000.2525 or higher; Windows Server 2022 should be 10.0.20348.5386 or hi
Caveat Standard Windows update risks - ensure backups exist and compatibility testing performed for business-critical applications

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

Fix this in Windows 10 21h2 Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing8.0 h
  • Review / QA3.0 h
17.0 hours of engineering $2,900
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-50459 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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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-2026-50459 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