CVE-2026-88071: CWE-415: Double Free in Microsoft Windows 11 version 23H2

CVE-2026-88071 is a double free vulnerability (CWE-415) in the Windows Hyper-V component of Microsoft Windows 11 version 23H2. This vulnerability permits an authorized attacker with local access to elevate privileges by exploiting improper memory management. The vulnerability affects several builds of Windows 11 23H2, specifically those with build numbers >=10.0.20348.0 and <10.0.20348.5761, >=10.0.22631.0 and <10.0.22631.7652, >=10.0.26100.0 and <10.0.26100.9711, >=10.0.26100.0 and <10.0.26100.33650, >=10.0.26200.0 and <10.0.26200.9711, and >=10.0.26300.0 and <10.0.26300.9711. The vulnerability has a CVSS v3.1 base score of 7.8, indicating high severity. Microsoft has released an official fix for this issue.

An authorized local attacker can exploit this double free vulnerability in Windows Hyper-V to elevate their privileges, potentially gaining higher-level access on the affected system. The impact includes full confidentiality, integrity, and availability compromise as indicated by the CVSS vector (C:H/I:H/A:H). There are no known exploits in the wild at this time.

An official fix is available from Microsoft. Users and administrators should apply the security updates provided by Microsoft for Windows 11 version 23H2 to remediate this vulnerability. Refer to the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-88071 for update details and installation instructions.