A heap‑based buffer overflow exists in the Windows Universal Plug and Play (UPnP) Device Host component. The flaw enables a local attacker who can interact with the service to overflow a buffer, which can be used to gain elevated privileges on the system. The security impact is a loss of integrity and confidentiality for the local user, allowing execution of code with higher privileges that may compromise the entire machine.

Microsoft Windows 10 versions 1607, 1809, 21H2, 22H2; Windows 11 versions 23H2, 24H2, 25H2, 26H2, 26H1; Windows Server 2012 – 2025 including core installations. All listed releases are affected until updated with the official fix.

The CVSS base score of 7.8 indicates a moderate‑to‑high severity. The vulnerability requires local authorization; an attacker must have either legitimate access or be able to execute code locally to exploit the flaw. EPSS data is unavailable, so the exact likelihood of exploitation cannot be quantified, and the vulnerability is not currently listed in the CISA KEV catalog. Because a local attacker can trigger the buffer overflow through UPnP interfaces, the risk of privilege escalation remains significant until the issued fix or mitigations are applied.