cvss-score-extraction

name	cvss-score-extraction
description	Extract CVSS scores from Trivy vulnerability data with proper source priority fallback (NVD > GHSA > RedHat).

CVSS Score Extraction

Source Priority

NVD (most authoritative) → GHSA → RedHat → N/A

Always prefer CVSS v3 scores. Fall back to v2 only if v3 unavailable.

Implementation

def get_cvss_score(vuln_data):
    """Extract best available CVSS v3 score. Returns float or 'N/A'."""
    cvss = vuln_data.get('CVSS', {})
    for source in ['nvd', 'ghsa', 'redhat']:
        if source in cvss:
            score = cvss[source].get('V3Score')
            if score is not None:
                return score
    return 'N/A'

Trivy CVSS Data Format

"CVSS": {
  "nvd": {
    "V2Score": 7.5,
    "V3Score": 9.8,
    "V3Vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  },
  "ghsa": {
    "V3Score": 9.8
  }
}

Score Severity Mapping

Score	Severity
9.0-10.0	CRITICAL
7.0-8.9	HIGH
4.0-6.9	MEDIUM
0.1-3.9	LOW