An integer underflow (wrap or wraparound) in the Windows Bluetooth A2DP driver (CWE-191) allows an authorized attacker to elevate privileges over an adjacent network. The flaw permits the attacker to manipulate internal calculations, potentially causing the driver to execute code with higher privileges, which can compromise the entire system or any services running under a lower privilege context.

Microsoft Windows 10 with versions 1607, 1809, 21H2, and 22H2; Microsoft Windows 11 with versions 23H2, 24H2, 25H2, 26H2, and 26H1; and Microsoft Windows Server releases 2016, 2019, 2022, and 2025 are affected by this flaw.

The CVSS score of 8 indicates high severity. The EPSS score is less than 1%, indicating a very low probability of exploitation. The vulnerability is not listed in the CISA KEV catalog. The likely attack vector is local or adjacent, as the description references an attacker connected over an adjacent network and requiring authorized access. Integer underflow allows manipulation of driver operations leading to privilege escalation. Because the flaw resides in a system driver, exploitation requires effective system context and the fix is contained within the Microsoft update.