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CVE-2026-45654 Microsoft CVE debrief

CVE-2026-45654 is a HIGH-severity vulnerability in Windows Secure Boot, allowing an authorized attacker to bypass a security feature locally. The vulnerability has a CVSS score of 7.9 and was published on 2026-06-09T17:17:32.460Z. The CVE was modified on 2026-06-11T18:51:33.450Z. The vulnerability affects multiple versions of Windows 11 and Windows Server 2025.

Vendor
Microsoft
Product
Windows 11 Version 24H2
CVSS
HIGH 7.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-09
Original CVE updated
2026-07-09
Advisory published
2026-06-09
Advisory updated
2026-07-09

Who should care

Administrators and users of Windows 11 and Windows Server 2025 should be aware of this vulnerability and take necessary actions to mitigate it.

Technical summary

The vulnerability is caused by a protection mechanism failure in Windows Secure Boot, allowing an authorized attacker to bypass a security feature locally. The vulnerability has been assigned CWE-284.

Defensive priority

HIGH

Recommended defensive actions

  • Apply patches or updates provided by Microsoft to fix the vulnerability.
  • Refer to [ref-4](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45654) for mitigation or vendor reference.

Evidence notes

The vulnerability is analyzed and has been assigned a CVSS vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-45654 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-45654

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-45654 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-45654

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.