dbcve.org
Windows 11 23h2Operating system · Microsoft

CVE-2026-20938

HIGH · 7.8 CVSS v3.1 Published 2026-01-13
Fix available
A fix is available. Upgrade to 10.0.22631.6491 / 10.0.26100.7623 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

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
Untrusted pointer dereference in Windows Virtualization-Based Security (VBS) Enclave allows an authorized attacker to elevate privileges locally.

In the news

Third-party coverage
Trending covered by 1 outlet this week · latest 7mo 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

This vulnerability is an untrusted pointer dereference flaw in Windows Virtualization-Based Security (VBS) Enclave, a Windows security feature that uses hardware virtualization to create isolated secure regions. The flaw allows a locally authorized attacker to dereference an untrusted pointer, leading to privilege elevation from their current authorization level to higher system privileges.

MitigationApply the Microsoft security update for CVE-2026-20938 when available. Prioritize patching systems with VBS enabled, particularly enterprise endpoints and servers where VBS is commonly deployed for credential protection and isolated Trusted Platform Module functionality.

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 23h2Operating system
Affected:< 10.0.22631.6491
Windows 11 24h2Operating system
Affected:< 10.0.26100.7623
Windows 11 25h2Operating system
Affected:< 10.0.26200.7623

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 installed Windows 11 version
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Version"' to obtain the full build number. Compare it to the affected version thresholds: 23h2 builds below 10.0.22631.6491, 24h2 builds below 10.0.26100.7623, and 25h2 builds below 10.0.26200.7623 are vulnerable.
    Affected if The installed Windows 11 version falls within the affected build ranges and VBS Enclave is enabled.
  2. Confirm VBS Enclave is enabled
    Run 'msinfo32' and look for 'Virtualization-Based Security' in the summary, or run 'Get-ComputerInfo | Select-Object -ExpandProperty CsVirtualizationBasedSecurityStatus' in PowerShell. Check registry key 'HKLM\SYSTEM\CurrentControlSet\Control\DeviceGuard' for 'EnableVirtualizationBasedSecurity' set to 1.
    Affected if VBS is running (VBS Enclave must be active for this vulnerability to be exploitable).
  3. Verify VBS configuration state
    Run 'Get-ComputerInfo' and examine 'DeviceGuardCodeIntegrityPolicyEnforcementStatus' and 'DeviceGuardSecurityServicesConfigured' to see if VBS security services are configured, which indicates active VBS protection.
    Affected if VBS security services are configured and running, making the environment susceptible to this pointer dereference flaw.

You are affected if your Windows 11 version is below the fixed builds AND VBS Enclave is currently enabled on your system.

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 10.0.22631.6491 / 10.0.26100.7623 / 10.0.26200.7623 or later
Fixed in 10.0.22631.649110.0.26100.762310.0.26200.7623
Interim mitigation

Apply the Microsoft security update for CVE-2026-20938 when available. Prioritize patching systems with VBS enabled, particularly enterprise endpoints and servers where VBS is commonly deployed for credential protection and isolated Trusted Platform Module functionality.

Recommended fix High confidence

Windows 11 23h2: 10.0.22631.6491 or later | Windows 11 24h2: 10.0.26100.7623 or later | Windows 11 25h2: 10.0.26200.7623 or later

  1. Check current Windows version by running 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"'
  2. Open Settings > Windows Update
  3. Click 'Check for updates' to download and install the latest security updates
  4. Restart the system when prompted to complete the installation
  5. Verify the installed version meets the minimum: 10.0.22631.6491 (23h2), 10.0.26100.7623 (24h2), or 10.0.26200.7623 (25h2)
Caveat Standard Windows cumulative update; minimal risk but may require restart

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

Fix this in Windows 11 23h2 Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
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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-2026-20938 in production — separate from our analysis above.

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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