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PatchSiren cyber security CVE debrief

CVE-2026-81355 Microsoft CVE debrief

A heap-based buffer overflow vulnerability exists in the Virtual Hard Disk (VHD) Miniport Driver, potentially allowing an authorized attacker to execute code locally. Multiple Windows versions and server releases are affected, including Windows 10, Windows 11, and various Windows Server editions. Microsoft has provided a vendor advisory for this issue.

Vendor
Microsoft
Product
Windows 10 Version 1607
CVSS
HIGH 7.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-08
Original CVE updated
2026-09-23
Advisory published
2026-09-08
Advisory updated
2026-09-23

Who should care

Defenders responsible for Windows 10, Windows 11, and Windows Server environments should assess exposure and prioritize patching. This includes administrators of workstations, servers, and cloud infrastructure running affected versions. Security teams should verify system configurations against the provided CPE criteria and monitor for updates from Microsoft.

Why it matters

CVE-2026-81355 is a high-severity vulnerability in the Virtual Hard Disk (VHD) Miniport Driver that could allow authorized attackers to execute code locally. Defenders should prioritize patching, assess exposure, verify system configurations, and monitor for updates from Microsoft.

  • Local code execution potential requires immediate patching priority
  • Exposure assessment is critical for Windows environments
  • Verification of system configurations against CPE criteria is necessary
  • Monitoring for Microsoft updates is essential for remediation

Technical summary

The CVE-2026-81355 vulnerability is a heap-based buffer overflow in the Virtual Hard Disk (VHD) Miniport Driver. This issue allows an authorized attacker to potentially execute code locally. The vulnerability has a CVSS score of 7.5 and is classified as CWE-122. Multiple versions of Windows 10, Windows 11, and various Windows Server editions are affected, including Windows 10 1607, Windows 10 1809, Windows 10 21H2, Windows 10 22H2, Windows 11 23H2, Windows 11 24H2, Windows 11 25H2, Windows 11 26H1, Windows Server 2012, Windows Server 2012 R2, Windows Server 2016, Windows Server 2019, Windows Server 2022, and Windows Server 2025.

Defensive priority

High

Recommended defensive actions

  • Review and apply the vendor advisory from Microsoft
  • Assess exposure for Windows 10, Windows 11, and Windows Server environments
  • Verify system configurations against the provided CPE criteria
  • Monitor for updates from Microsoft regarding this vulnerability

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its CVSS score of 7.5 and a CVSS vector of AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H. The vulnerability is classified under CWE-122. Microsoft has provided a vendor advisory for this issue.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-81355 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-81355

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

  • CVE-2026-81355 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-81355

    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.