This vulnerability, identified as CWE-131, involves an incorrect calculation of buffer size within the Windows VMSwitch component in Windows 10 Version 21H2 (build 10.0.19044.0). An authorized attacker with local privileges can exploit this flaw to cause a denial of service condition by triggering improper buffer handling. The issue does not affect data confidentiality or integrity but results in service disruption. Microsoft has published an official fix to address this vulnerability.

The vulnerability allows a local, authorized attacker to cause a denial of service on the affected system by exploiting incorrect buffer size calculations in the Windows VMSwitch component. There is no impact on confidentiality or integrity. The CVSS v3.1 base score is 5.5 (medium severity), reflecting the local attack vector, low complexity, required privileges, and no user interaction.

An official fix is available from Microsoft. Users and administrators should apply the security update provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42915 to remediate this vulnerability. No additional mitigation actions are required beyond applying the official patch.