run2-cvss-score

name	run2_cvss-score
description	Extract CVSS v3 scores from Trivy vulnerability data with source priority fallback (NVD > GHSA > RedHat) and handle missing data gracefully.

CVSS Score Extraction from Trivy Data

CVSS Sources in Trivy Output

Trivy provides CVSS scores from multiple sources in the CVSS field:

• nvd: National Vulnerability Database (most authoritative)
• ghsa: GitHub Security Advisory
• redhat: Red Hat security team

Not all sources are present for every vulnerability.

Recommended Priority: NVD > GHSA > RedHat

NVD is the standard reference. GHSA is widely used for npm/GitHub ecosystems. RedHat is useful as a fallback.

Python Implementation

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

Real-world examples from npm scanning

• CVE-2024-29415 (ip): Only ghsa (8.1) and redhat (9.8) — no NVD score → returns 8.1
• CVE-2022-25883 (semver): All three sources at 7.5 → returns 7.5
• CVE-2026-23745 (tar): Only redhat (8.2) → returns 8.2