Vulnerability · Published May 12, 2026 · Assigned by microsoft
CVE-2026-40402Windows Hyper-V Elevation of Privilege Vulnerability
Critical 9.3
In plain English
A critical-severity use-after-free in Windows 11 version 23H2 from Microsoft. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 27% of all known vulnerabilities).
Severity (CVSS 3.1)9.3Critical
Exploit odds (30 days)0.3%top 73.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Use after free in Windows Hyper-V allows an unauthorized attacker to elevate privileges locally.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Windows 11 version 23H2 | 10.0.22631.0 – before 10.0.22631.7079 |
| Microsoft | Windows 11 Version 23H2 | 10.0.22631.0 – before 10.0.22631.7219 |
| Microsoft | Windows Server 2022 | 10.0.20348.0 – before 10.0.20348.5139 |
Weakness: CWE-416 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C
References
- Windows Hyper-V Elevation of Privilege Vulnerability vendor-advisory, patch