CVE-2026-40402

Name: CVE-2026-40402
Creator: NVD / NIST
Published: 2026-05-12T18:17:18+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.3/10EPSS 0.33%

Last modified Jun 17, 2026

CVE-2026-40402 is a critical-severity vulnerability rated 9.3/10 on the CVSS scale. Use after free in Windows Hyper-V allows an unauthorized attacker to elevate privileges locally.. EPSS estimates a 0.33% chance of exploitation in the next 30 days.

Description

Use after free in Windows Hyper-V allows an unauthorized attacker to elevate privileges locally.

Metrics

CVSS 3.1

9.3/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS Probability

0.33%

25.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-416

Affected Software

Vendor	Product	Versions
Microsoft	Windows 11 23h2	< 10.0.22631.7079
Microsoft	Windows Server 2022	< 10.0.20348.5074

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40402Vendor Advisory

Timeline

Published: May 12, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-40402?

Use after free in Windows Hyper-V allows an unauthorized attacker to elevate privileges locally.

How severe is CVE-2026-40402?

CVE-2026-40402 has a CVSS score of 9.3/10 (CRITICAL severity). The EPSS model estimates a 0.33% probability of exploitation in the next 30 days.

How do I fix CVE-2026-40402?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-40402?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST