Comprehensive and Detailed Explanation From Exact Extract:
CVSS scores are classified into severity levels based on numeric ranges. A base score of 9.9 falls within the Critical range (9.0-10.0), but after adjustment for temporal and environmental metrics, the score is 8.0, which falls into the High severity category (7.0-8.9). Therefore, the final rating assigned is High severity.
Medium severity corresponds to scores between 4.0 and 6.9, and low severity is below 4.0. This scoring methodology is defined by the FIRST Common Vulnerability Scoring System v3.1 Specification which guides how scores are adjusted to reflect real-world risk contexts.
References:
FIRST CVSS v3.1 Specification
OWASP Vulnerability Severity Classification
NIST National Vulnerability Database (NVD)