dbcve.org
Windows 10 1607Operating system · Microsoft

CVE-2026-27911

HIGH · 7.8 CVSS v3.1 Published 2026-04-14
Fix available
A fix is available. Upgrade to 10.0.14393.9060 / 10.0.17763.8644 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
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows User Interface Core allows an authorized attacker to elevate privileges locally.

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 is a race condition vulnerability in Windows User Interface Core where improper synchronization of shared resources allows a locally authorized attacker to elevate privileges. The vulnerability stems from concurrent access to shared state without adequate locking mechanisms, enabling an attacker to manipulate timing to achieve privilege escalation.

MitigationApply the Microsoft security update for CVE-2026-27911 once released. As a defensive measure, monitor for suspicious processes attempting to interact with UI Core components and restrict local administrative privileges where possible.

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:< 10.0.14393.9060
Windows 10 1809Operating system
Affected:< 10.0.17763.8644
Windows 10 21h2Operating system
Affected:< 10.0.19044.7184
Windows 10 22h2Operating system
Affected:< 10.0.19045.7184
Windows 11 23h2Operating system
Affected:< 10.0.22631.6936
Windows 11 24h2Operating system
Affected:< 10.0.26100.8246
Windows 11 25h2Operating system
Affected:< 10.0.26200.8246
Windows 11 26h1Operating system
Affected:< 10.0.28000.1836

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

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/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 version and build number
    Run 'winver' from command prompt or check System Properties, or run 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to retrieve the exact version and build number
    Affected if The displayed version falls within any of the affected ranges and is lower than the fixed build numbers (14393.9060, 17763.8644, 19044.7184, 19045.7184, 22631.6936, 26100.8246, 26200.8246, 28000.1836)
  2. Verify Windows edition
    Run 'winver' or check System Properties to confirm if the system is Windows 10 or Windows 11, as the vulnerability affects specific Windows 10 and Windows 11 versions only
    Affected if The system is running Windows 10 version 1607, 1809, 21h2, 22h2 or Windows 11 versions 23h2, 24h2, 25h2, 26h1 with a build number below the fixed threshold
  3. Confirm UI Core component presence
    Check that the Windows User Interface Core components are present on the system - these are core Windows GUI components typically found in %SystemRoot%\System32\ui*.dll files
    Affected if The UI Core components exist on the system (vulnerability resides in these components)
  4. Check for pending security updates
    Open Windows Update settings and check 'Update history' for installed security updates, or run 'wmic qfe list' to see installed hotfixes
    Affected if No security update for CVE-2026-27911 has been installed, indicating the vulnerability remains unpatched

A system is affected if it runs any of the listed Windows 10 or 11 versions with a build number lower than the fixed threshold and has not received the corresponding security update for CVE-2026-27911.

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 10.0.14393.9060 / 10.0.17763.8644 / 10.0.19044.7184 or later
Fixed in 10.0.14393.906010.0.17763.864410.0.19044.7184
Interim mitigation

Apply the Microsoft security update for CVE-2026-27911 once released. As a defensive measure, monitor for suspicious processes attempting to interact with UI Core components and restrict local administrative privileges where possible.

Recommended fix High confidence

Upgrade to the respective fixed build: Windows 10 1607 to 10.0.14393.9060 | Windows 10 1809 to 10.0.17763.8644 | Windows 10 21h2 to 10.0.19044.7184 | Windows 10 22h2 to 10.0.19045.7184 | Windows 11 23h2 to 10.0.22631.6936 | Windows 11 24h2 to 10.0.26100.8246 | Windows 11 25h2 to 10.0.26200.8246 | Wi

  1. Identify the current Windows build version by running 'winver' or 'systeminfo | findstr /C:"Build"' in Command Prompt
  2. Open Settings > Windows Update and check for updates, or manually download the appropriate cumulative update from the Microsoft Update Catalog for your Windows version
  3. Install theKB update that addresses CVE-2026-27911 (refer to Microsoft Security Response Center for the specificKB number)
  4. Restart the system to apply the update
  5. Verify the installation by checking that the build number matches or exceeds the fixed version for your Windows release
Caveat Standard Windows update risks - ensure backups and test in non-production environments before deploying broadly 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
  • Consultation4.0 h
  • Implementation16.0 h
  • Testing8.0 h
  • Review / QA4.0 h
32.0 hours of engineering $5,600
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,960.

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-2026-27911 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