CVE-2026-96939: CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition in Microsoft Windows 11 version 23H2

This vulnerability involves a TOCTOU race condition in the Servicing Stack Updates of Windows 11 version 23H2. An attacker with local authorized access can exploit this timing flaw to gain elevated privileges. The issue affects several specific builds of Windows 11 23H2, as identified by their build numbers. Microsoft has published an official fix to remediate the vulnerability.

Successful exploitation allows an authorized local attacker to elevate privileges, potentially gaining higher system rights than intended. The vulnerability impacts confidentiality, integrity, and availability, 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 for Windows 11 version 23H2 as provided in the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-96939. Applying these patches will mitigate the vulnerability.