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 (CVE-2026-40402) is a use-after-free flaw in the Windows Hyper-V component of Windows 11 version 23H2 (build 10.0.22631.0). Exploitation allows an unauthorized local attacker to elevate privileges, potentially gaining higher system rights. The CVSS v3.1 score is 9.3 (critical) reflecting local attack vector with low complexity, no privileges required, no user interaction, and complete impact on confidentiality, integrity, and availability. Microsoft has released an official fix for this vulnerability as documented in their security update guide.
Potential Impact
An attacker with local access can exploit this use-after-free vulnerability to elevate privileges, compromising system confidentiality, integrity, and availability. This could lead to full system compromise if exploited successfully.
Mitigation Recommendations
Apply the official security update provided by Microsoft for Windows 11 version 23H2 (build 10.0.22631.0) to remediate this vulnerability. The vendor advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40402 contains the patch details and should be followed for remediation.
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
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-40402) is a use-after-free flaw in the Windows Hyper-V component of Windows 11 version 23H2 (build 10.0.22631.0). Exploitation allows an unauthorized local attacker to elevate privileges, potentially gaining higher system rights. The CVSS v3.1 score is 9.3 (critical) reflecting local attack vector with low complexity, no privileges required, no user interaction, and complete impact on confidentiality, integrity, and availability. Microsoft has released an official fix for this vulnerability as documented in their security update guide.
Potential Impact
An attacker with local access can exploit this use-after-free vulnerability to elevate privileges, compromising system confidentiality, integrity, and availability. This could lead to full system compromise if exploited successfully.
Mitigation Recommendations
Apply the official security update provided by Microsoft for Windows 11 version 23H2 (build 10.0.22631.0) to remediate this vulnerability. The vendor advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40402 contains the patch details and should be followed for remediation.
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: 06/19/2026, 17:38:54 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 73
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