Vulnerabilities
CVSS
Also: Common Vulnerability Scoring System
A standard 0 to 10 score of a vulnerability's technical severity.
In more detail
Scores of 9.0 and above are rated critical. CVSS describes how bad a flaw could be, not how likely it is to be attacked or whether it matters in your setup, so combine it with exploit data (EPSS, KEV) and your own exposure.