dbcve.org
Windows 11 24h2Operating system · Microsoft

CVE-2026-54127

HIGH · 8.4 CVSS v3.1 Published 2026-07-14
Fix available
A fix is available. Upgrade to 10.0.20348.5386 / 10.0.26100.8875 or later.
See remediation →
89/100
Remediation priority · High
No privileges 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 Hyper-V 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 in Windows Hyper-V permits a local attacker to gain elevated privileges. The vulnerability involves improper memory management where memory is accessed after being freed, potentially allowing arbitrary code execution with higher privileges.

MitigationApply Microsoft security updates for Windows Hyper-V as they become available. Prioritize patching systems where untrusted VM guests can communicate with the host.

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

CVSS:3.1/AV:L/AC:L/PR:N/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. Verify Hyper-V is enabled
    Run 'Get-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V' in PowerShell or check Programs and Features for Hyper-V
    Affected if Hyper-V is installed and the host is running an affected Windows version
  2. Check Windows version number
    Run 'winver' from Run dialog, or 'systeminfo' in Command Prompt, or '(Get-ItemProperty -Path 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion').CurrentBuild' in PowerShell
    Affected if The Windows version/build number falls below the fixed version for your specific Windows release
  3. Compare against affected version ranges
    Match your Windows edition and build to: Windows 11 24h2 (< 10.0.26100.8875), Windows 11 25h2 (< 10.0.26200.8875), Windows 11 26h1 (< 10.0.28000.2525), Windows Server 2022 (< 10.0.20348.5386), Windows Server 2025 (< 10.0.26100.33158)
    Affected if Your installed version is lower than the fixed version for your Windows edition

You are affected if Hyper-V is enabled and your Windows version is below the fixed build number for your specific Windows edition.

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 10.0.20348.5386 / 10.0.26100.8875 / 10.0.26100.33158 or later
Fixed in 10.0.20348.538610.0.26100.887510.0.26100.33158
Interim mitigation

Apply Microsoft security updates for Windows Hyper-V as they become available. Prioritize patching systems where untrusted VM guests can communicate with the host.

Recommended fix High confidence

Apply Microsoft security updates via Windows Update that bring the build version to the fixed release or later. Specific KB articles can be found on the Microsoft Security Response Center (msrc.microsoft.com).

  1. Open Windows Settings on the affected system
  2. Navigate to Windows Update > Check for updates
  3. Install all available security updates, particularly those addressing Hyper-V vulnerabilities
  4. After updates are installed, restart the system to apply the kernel/hypervisor patches
  5. Verify the installed build version matches or exceeds: 10.0.26100.8875 (Win11 24h2), 10.0.26200.8875 (Win11 25h2), 10.0.28000.2525 (Win11 26h1), 10.0.20348.5386 (Server 2022), or 10.0.26100.33158 (Server 2025)
Caveat Standard Windows update applies—review release notes for any known compatibility issues with Hyper-V workloads before updating production systems

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

Fix this in Windows 11 24h2 Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing8.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,680
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,288.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-54127 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2026-54127 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