CVE-2026-40402 — CRITICAL (9.3)

Q: What is CVE-2026-40402?

CVE-2026-40402 is a vulnerability with a CVSS score of 9.3 (CRITICAL). Use after free in Windows Hyper-V allows an unauthorized attacker to elevate privileges locally.

Q: How severe is CVE-2026-40402?

CVE-2026-40402 has been rated CRITICAL with a CVSS base score of 9.3/10. This is considered a critical vulnerability requiring immediate attention.

Q: Is there a patch for CVE-2026-40402?

Check the references section above for vendor advisories and patch information. Affected products include: Microsoft Windows 11 23H2, Microsoft Windows Server 2022.

Vulnerability Description

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

CVSS Score

9.3

CRITICAL

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

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

CHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

Affected Products

Vendor	Product	Versions
Microsoft	Windows 11 23H2	< 10.0.22631.7079
Microsoft	Windows Server 2022	< 10.0.20348.5074

Related Weaknesses (CWE)

CWE-416

References

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

FAQ

What is CVE-2026-40402?

CVE-2026-40402 is a vulnerability with a CVSS score of 9.3 (CRITICAL). 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 been rated CRITICAL with a CVSS base score of 9.3/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2026-40402?

Check the references section above for vendor advisories and patch information. Affected products include: Microsoft Windows 11 23H2, Microsoft Windows Server 2022.