Implementing EPSS Score for Vulnerability Prioritization

Overview

The Exploit Prediction Scoring System (EPSS) is a data-driven model developed by FIRST (Forum of Incident Response and Security Teams) that estimates the probability of a CVE being exploited in the wild within the next 30 days. EPSS produces scores from 0.0 to 1.0 (0% to 100%) using machine learning trained on real-world exploitation data. Unlike CVSS which measures severity, EPSS measures likelihood of exploitation, making it essential for risk-based vulnerability prioritization.

When to Use

• When deploying or configuring implementing epss score for vulnerability prioritization capabilities in your environment
• When establishing security controls aligned to compliance requirements
• When building or improving security architecture for this domain
• When conducting security assessments that require this implementation

Prerequisites

• Python 3.9+ with requests, pandas, matplotlib
• Access to FIRST EPSS API (https://api.first.org/data/v1/epss)
• Vulnerability scan results with CVE identifiers