Windows Hyper-V Remote Code Execution Vulnerability

Heap-based buffer overflow in Windows Hyper-V allows an unauthorized attacker to execute code locally.

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7.8CVSS out of 10High severity

Scope

What the vendor says is affected

Windows 11 Version 26H1 for ARM64-based Systems
Windows 11 version 26H1 for x64-based Systems
Windows 10 Version 1809 for x64-based Systems
Windows Server 2019
Windows Server 2019 (Server Core installation)
Windows Server 2022
Windows Server 2022 (Server Core installation)
Windows 10 Version 21H2 for x64-based Systems
Windows 10 Version 22H2 for x64-based Systems
Windows Server 2025 (Server Core installation)
Windows 11 Version 25H2 for ARM64-based Systems
Windows 11 Version 25H2 for x64-based Systems
Windows 11 Version 23H2 for ARM64-based Systems
Windows 11 Version 23H2 for x64-based Systems
Windows Server 2022, 23H2 Edition (Server Core installation)
Windows 11 Version 24H2 for ARM64-based Systems
Windows 11 Version 24H2 for x64-based Systems
Windows Server 2025
Windows 10 Version 1607 for x64-based Systems
Windows Server 2016
Windows Server 2016 (Server Core installation)

Versions the vendor lists as fixed

10.0.28000.1836
10.0.17763.8644
10.0.20348.5020
10.0.19044.7184
10.0.19045.7184
10.0.26100.32690
10.0.26200.8246
10.0.22631.6936
10.0.25398.2274
10.0.26100.8246
10.0.14393.9060

Next step

What the vendor recommends

Install KB5083768. Install KB5082123. Install KB5082142. Install KB5082200. Install KB5082063. Install KB5083769. Install KB5082052. Install KB5082060. Install KB5082198.

Review the complete instructions on the vendor's site

Timeline

When this advisory changed

Apr 14, 2026 at 7:00 AM UTC
Published by Microsoft Security Response Center
The publication date reported by the vendor.
Sep 27, 2026 at 11:11 PM UTC
Added to SecurityAlert
We collected the advisory from the official source.

Vulnerabilities

CVEs named in this advisory

CVE-2026-26156View CVSS, KEV, EPSS, and threat context

Source

Start with the vendor's bulletin

SecurityAlert organizes the fields the vendor published. The original bulletin remains the source of record for affected versions, fixes, and later changes.

Vendor: Microsoft Security Response Center
Advisory ID: CVE-2026-26156
Last source check: Sep 27, 2026 at 11:11 PM UTC

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What the vendor says is affected

Versions the vendor lists as fixed

What the vendor recommends

When this advisory changed

CVEs named in this advisory

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