CRITICAL 9.3 Microsoft
CVE-2026-40402
Windows Hyper-V Elevation of Privilege Vulnerability
Microsoft Security Update 2026-May: Windows Hyper-V Elevation of Privilege Vulnerability
Affected Products
- Windows Server 2022
- Windows Server 2022 (Server Core installation)
- Windows 11 Version 23H2 for ARM64-based Systems
- Windows 11 Version 23H2 for x64-based Systems
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40402
- https://nvd.nist.gov/vuln/detail/CVE-2026-40402
This critical severity vulnerability with a CVSS score of 9.3 was published on 2026-05-12 via Microsoft. Affected: Windows Server 2022, Windows Server 2022 (Server Core installation), Windows 11 Version 23H2 for ARM64-based Systems and 1 more.
Risk Timeline
CVE Disclosed2026-05-12 · 128 days ago
Remediation Resources
Official Advisory
msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40402NVD / MITRE
nvd.nist.gov/vuln/detail/CVE-2026-40402Related Vulnerabilities
| CVE | Title | Severity | CVSS |
|---|---|---|---|
| CVE-2026-57092 | Microsoft Windows VMSwitch Elevation of Privilege Vulnerability | CRITICAL | 9.9 |
| CVE-2026-68839 | Windows USB Mass Storage Class Driver Remote Code Execution Vulnerability | CRITICAL | 9.8 |
| CVE-2026-69276 | Microsoft UxTheme Library (uxtheme.dll) Remote Code Execution Vulnerability | CRITICAL | 9.8 |
| CVE-2026-69408 | Microsoft Windows Media Foundation Remote Code Execution Vulnerability | CRITICAL | 9.8 |
| CVE-2026-69431 | Telnet Client Remote Code Execution Vulnerability | CRITICAL | 9.8 |
| CVE-2026-69463 | Windows NTFS Remote Code Execution Vulnerability | CRITICAL | 9.8 |
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