This vulnerability involves a numeric truncation error in the Windows Universal Disk Format File System Driver (UDFS) on Windows 10 Version 1607 (build 10.0.14393.0). The flaw could be exploited by an attacker with low privileges to gain elevated privileges on the affected system. The CVSS v3.1 base score is 7.8, indicating high severity, with attack vector local, low attack complexity, low privileges required, no user interaction, and impacts to confidentiality, integrity, and availability. Microsoft has released an official fix to address this vulnerability.

Successful exploitation of this vulnerability could allow an attacker with limited privileges to elevate their privileges to a higher level, potentially gaining full control over the affected system. This could lead to complete compromise of confidentiality, integrity, and availability of the system.

An official fix is available from Microsoft. Users and administrators should apply the security update provided by Microsoft for Windows 10 Version 1607 (build 10.0.14393.0) as soon as possible to remediate this vulnerability. Refer to the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40409 for update details and installation instructions.