CVE-2026-40402: CWE-416: Use After Free in Microsoft Windows 11 version 23H2
Use after free in Windows Hyper-V allows an unauthorized attacker to elevate privileges locally.
AI Analysis
Technical Summary
This vulnerability, identified as CVE-2026-40402 and classified under CWE-416 (Use After Free), affects Windows Hyper-V in Windows 11 version 23H2 (build 10.0.22631.0). It allows a local attacker without privileges to exploit a use-after-free condition to elevate their privileges on the affected system. The vulnerability has a CVSS v3.1 base score of 9.3, indicating critical severity with high impact on confidentiality, integrity, and availability. Microsoft has published an official fix to remediate this issue.
Potential Impact
Successful exploitation of this vulnerability could allow an unauthorized local attacker to gain elevated privileges, potentially leading to full system compromise. The CVSS score of 9.3 reflects critical impact on system confidentiality, integrity, and availability.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided by Microsoft for Windows 11 version 23H2 (build 10.0.22631.0) as soon as possible. Refer to the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40402 for detailed patching instructions.
CVE-2026-40402: CWE-416: Use After Free in Microsoft Windows 11 version 23H2
Description
Use after free in Windows Hyper-V allows an unauthorized attacker to elevate privileges locally.
CVSS v3.1
Score 9.3critical
Affected software
Microsoft
Windows 11 version 23H2
Microsoft
Windows 11 Version 23H2
Microsoft
Windows Server 2022
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability, identified as CVE-2026-40402 and classified under CWE-416 (Use After Free), affects Windows Hyper-V in Windows 11 version 23H2 (build 10.0.22631.0). It allows a local attacker without privileges to exploit a use-after-free condition to elevate their privileges on the affected system. The vulnerability has a CVSS v3.1 base score of 9.3, indicating critical severity with high impact on confidentiality, integrity, and availability. Microsoft has published an official fix to remediate this issue.
Potential Impact
Successful exploitation of this vulnerability could allow an unauthorized local attacker to gain elevated privileges, potentially leading to full system compromise. The CVSS score of 9.3 reflects critical impact on system confidentiality, integrity, and availability.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided by Microsoft for Windows 11 version 23H2 (build 10.0.22631.0) as soon as possible. Refer to the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40402 for detailed patching instructions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-04-13T00:27:50.798Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40402","vendor":"Microsoft"}]
Threat ID: 6a036554cbff5d861008c974
Added to database: 05/12/2026, 17:37:24 UTC
Last enriched: 08/11/2026, 16:47:33 UTC
Last updated: 09/14/2026, 22:01:33 UTC
Views: 86
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