The Common Vulnerability Scoring System (CVSS) is an open standard designed to convey vulnerability severity and help determine the urgency and priority of response. When vulnerabilities are discovered in medical devices, medical device manufacturers, typically working with the Department of Homeland Security (DHS) National Cybersecurity and Communications Integration Center (NCCIC), use CVSS to provide a consistent and standardized way to communicate the severity of a vulnerability between multiple parties, including the medical device manufacturer, hospitals, clinicians, patients, NCCIC, and vulnerability researchers.
Read more about the CVSS on MTRE site.