Windows 11 24h2Operating system · Microsoft

CVE-2026-42829

HIGH · 7.8 CVSS v3.1 Published 2026-06-09
Fix available
A fix is available. Upgrade to 10.0.26100.8655 / 10.0.26200.8655 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
Improper access control in Windows Administrator Protection allows an authorized attacker to bypass a security feature 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 vulnerability in Windows Administrator Protection involves improper access control that allows a locally authorized attacker to bypass a security feature. The bypass likely permits escalation of privileges or circumvents Windows' admin protection mechanisms that normally require explicit user consent for administrative operations.

MitigationApply Microsoft security updates for Windows Administrator Protection when available. In the interim, restrict local administrator privileges, monitor for suspicious process activity, and ensure users follow least-privilege principles.

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:< 10.0.26100.8655
Windows 11 25h2Operating system
Affected:< 10.0.26200.8655
Windows 11 26h1Operating system
Affected:< 10.0.28000.2269

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 Windows build version
    Run 'winver' from command prompt or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to see installed Windows version and build number
    Affected if Build number is less than 10.0.26100.8655 for 24h2, less than 10.0.26200.8655 for 25h2, or less than 10.0.28000.2269 for 26h1
  2. Confirm Windows 11 edition
    Verify the system is running Microsoft Windows 11 (not Windows 10 or Windows Server) as only specific Windows 11 versions are affected
    Affected if System runs Windows 11 24h2, 25h2, or 26h1 with vulnerable build numbers
  3. Check Windows Administrator Protection status
    Windows Administrator Protection is a security feature in Windows 11. Check if it is enabled by searching for 'Administrator Protection' in Windows Security settings or reviewing related security policies
    Affected if Windows Administrator Protection feature is present and enabled on the system

User is affected if running Windows 11 24h2/25h2/26h1 with a build number below the specified thresholds AND Windows Administrator Protection feature is enabled.

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 10.0.26100.8655 / 10.0.26200.8655 / 10.0.28000.2269 or later
Fixed in 10.0.26100.865510.0.26200.865510.0.28000.2269
Interim mitigation

Apply Microsoft security updates for Windows Administrator Protection when available. In the interim, restrict local administrator privileges, monitor for suspicious process activity, and ensure users follow least-privilege principles.

Recommended fix High confidence

Windows 11 24h2: build 10.0.26100.8655 or later | Windows 11 25h2: build 10.0.26200.8655 or later | Windows 11 26h1: build 10.0.28000.2269 or later

  1. Open Settings > Windows Update and check for updates
  2. Ensure the installed build is 10.0.26100.8655 or higher for Windows 11 24h2, 10.0.26200.8655 or higher for Windows 11 25h2, or 10.0.28000.2269 or higher for Windows 11 26h1
  3. If the required build is not available, run Windows Update until the latest security updates are installed
  4. Alternatively, manually check the build version by running 'winver' or 'systeminfo' in Command Prompt
Caveat Standard Windows update precautions apply - ensure critical data is backed up before applying updates

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

Fix this in Windows 11 24h2 Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,690
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,304.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-42829 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2026-42829 in production — separate from our analysis above.

No notes yet

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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