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Windows 11 24h2Operating system · Microsoft

CVE-2026-45654

HIGH · 7.9 CVSS v3.1 Published 2026-06-09
Fix available
A fix is available. Upgrade to 10.0.26100.8655 / 10.0.26100.32995 or later.
See remediation →
81/100
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 Secure Boot 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 is an improper access control vulnerability in Windows Secure Boot that allows an authorized local attacker to bypass a security feature. The vulnerability stems from insufficient authorization checks within the Secure Boot chain, potentially allowing an attacker with local access to bypass Secure Boot protections and execute arbitrary code during the boot process.

MitigationApply Microsoft security updates for Windows when available, and review Secure Boot configuration policies to ensure only trusted operating systems and bootloaders are permitted.

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
Windows Server 2025Operating system
Affected:< 10.0.26100.32995

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

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N

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 number
    Run 'winver' from Start menu or execute 'systeminfo' in Command Prompt and locate the 'OS Version' field. Compare the full build number (for example, 10.0.26100.xxxx) against the affected version ranges: 24h2 builds before 10.0.26100.8655, 25h2 before 10.0.26200.8655, 26h1 before 10.0.28000.2269, and Server 2025 before 10.0.26100.32995
    Affected if The installed Windows version falls within any of the affected version ranges listed in the CVE
  2. Verify Secure Boot is enabled
    Open Settings > Privacy & Security > For developers > Secure Boot, or run 'msinfo32' and check the 'Secure Boot State' value. If available, also check 'Secure Boot Policy' status
    Affected if Secure Boot is currently enabled on the system (the bypass only has impact when Secure Boot protection is active)
  3. Confirm Secure Boot configuration status
    Execute 'Confirm-SecureBootUEFI' cmdlet in PowerShell. A return value of True indicates Secure Boot is enabled; False indicates it is disabled
    Affected if The command returns True, confirming Secure Boot is active and the vulnerability could potentially be exploited

The system is affected if it runs any Windows 11 24h2/25h2/26h2 or Windows Server 2025 version within the specified vulnerable build ranges AND has Secure Boot 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 / 10.0.26100.32995 / 10.0.26200.8655 or later
Fixed in 10.0.26100.865510.0.26100.3299510.0.26200.8655
Interim mitigation

Apply Microsoft security updates for Windows when available, and review Secure Boot configuration policies to ensure only trusted operating systems and bootloaders are permitted.

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 | Windows Server 2025 build 10.0.26100.32995 or later

  1. 1. Identify the current Windows build version by running 'winver' or 'systeminfo | findstr /B /C:"OS Version"'
  2. 2. Determine which Windows 11 version or Windows Server 2025 is installed (24h2, 25h2, 26h1, or Server 2025)
  3. 3. Apply the appropriate Windows security update from Microsoft Update Catalog or WSUS that addresses CVE-2026-45654
  4. 4. Verify the update was installed successfully by checking Windows Update history or reviewing installed KB articles
  5. 5. Confirm the build number has been updated to the fixed version: 10.0.26100.8655 or higher for Windows 11 24h2/Server 2025; 10.0.26200.8655 or higher for Windows 11 25h2; 10.0.28000.2269 or higher for Windows 11 26h1
Caveat Standard Windows cumulative update - minimal risk; ensure backups and test in non-production environment first

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
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.

Scan for this in your stack

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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-2026-45654 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