dbcve.org
Windows 10 1607Operating system · Microsoft

CVE-2026-56644

HIGH · 7.8 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 →
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 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 use-after-free vulnerability in the Windows Kernel enables a local authenticated attacker to elevate privileges to kernel level. Use-after-free occurs when memory is freed but still referenced, potentially allowing arbitrary code execution with elevated system privileges.

MitigationApply Microsoft security patches for the specific Windows Kernel vulnerability once released. Prioritize patching systems with direct user access as this is a local privilege escalation 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 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:< 10.0.28000.2525
Windows Server 2016Operating system
Affected:< 10.0.14393.9339

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 and run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to get the exact Windows version and build number
    Affected if The build number is lower than the fixed version for your specific Windows release (e.g., 14393.9339 for Windows 10 1607/Server 2016, 17763.9020 for Windows 10 1809, etc.)
  2. Confirm Windows edition
    Run 'winver' or check System Properties to confirm whether the system is Windows 10 (specifying which release like 1607, 1809, 21h2, 22h2), Windows 11 (24h2, 25h2, 26h1), or Windows Server 2016
    Affected if The system runs any of the affected products: Windows 10 1607, 1809, 21h2, 22h2; Windows 11 24h2, 25h2, 26h1; or Windows Server 2016
  3. Check installed security updates
    Open Control Panel > Programs > View installed updates, or run 'wmic qfe list' in Command Prompt to list installed hotfixes
    Affected if No security update corresponding to CVE-2026-56644 is installed for the detected Windows version
  4. Verify kernel build against threshold
    Run 'ver' at command prompt or check the kernel version in System Information, then compare the build number to the affected range thresholds
    Affected if The kernel build number falls within any of the vulnerable version ranges: <14393.9339, <17763.9020, <19044.7548, <19045.7548, <26100.8875, <26200.8875, or <28000.2525 depending on Windows release

The system is affected if it runs any of the listed Windows 10 releases, Windows 11 releases, or Windows Server 2016 with a build number lower than the corresponding fixed version for that release.

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 Microsoft security patches for the specific Windows Kernel vulnerability once released. Prioritize patching systems with direct user access as this is a local privilege escalation vector.

Recommended fix High confidence

Install the relevant Windows Security Update (CVE-2026-56644) that raises your build to the fixed version number for your product

  1. Open Windows Settings and navigate to Windows Update (Settings > Update & Security > Windows Update)
  2. Click 'Check for updates' to download and install the latest cumulative security update
  3. Alternatively, manually download the security update from the Microsoft Update Catalog (catalog.update.microsoft.com) by searching for the relevant KB article for your Windows version
  4. After installation, restart the system to apply the kernel-level patch
  5. Verify the build version matches or exceeds the fixed release: Windows 10 1607/Server 2016: 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
Caveat Windows security updates typically have minimal breaking changes; however, ensure compatibility with line-of-business applications before broad deployment in enterprise environments

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
  • Testing6.0 h
  • Review / QA3.0 h
15.0 hours of engineering $2,560
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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-2026-56644 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