# Vulnerability Intelligence - EPSS Score

> Vulnerability Intelligence - EPSS Score is a paid API for AI agents from vuln-intel.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-21).

Returns EPSS exploit-probability scores and percentiles for up to 10 CVEs, ranked and labeled with a high/elevated/low exploit-likelihood verdict.

## Facts

- Endpoint: GET https://vuln-intel.x402tookit.com/epss-score?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/vulnerability-intelligence-epss-score-0d1c7638
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_1jQxdY2KffmCRRaaGU5wM

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability vulnerability-intelligence-epss-score-0d1c7638
```

Example prompt: What are the EPSS exploit probability scores and risk verdicts for CVE-2021-44228, CVE-2023-4966, and CVE-2024-21412? Rank them from highest to lowest exploit likelihood.

## When to prefer this

Use this endpoint when you need quantitative exploit-probability data (EPSS) for up to 10 CVEs in a single call, especially for patch prioritization, triage, or reporting workflows that require ranked, verdicted output. Prefer this over CISA KEV endpoints when you need probabilistic scoring rather than binary known-exploitation status, and over generic vulnerability lookup endpoints when you specifically need EPSS metrics with a risk verdict.

## Known failure modes

- Invalid or malformed CVE ID format returns an error or places IDs in notChecked list
- Requesting more than 10 CVEs at once may result in truncation or rejection
- CVE IDs not yet in EPSS database return null scores
- Service degradation returns partial results with degraded=true flag
- Network timeout or upstream EPSS API unavailability

## How this service works

EPSS exploit-probability score and percentile for up to 10 CVEs, ranked, with a high/elevated/low verdict.

## Output

Returns a ranked list of CVE scores with each entry's EPSS probability (0–1), percentile rank among all CVEs, and a high/elevated/low verdict. Also includes an overall summary, reasoning for the verdict, thresholds used, source attribution, a timestamp (asOf), and optionally a list of CVE IDs that could not be checked (notChecked) and a degraded flag indicating partial data availability.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "cves"
     ],
     "properties": {
      "cves": {
       "type": "string",
       "description": "Comma-separated CVE ids, up to 10"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "scores": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "object",
        "properties": {
         "cve": {
          "type": [
           "null",
           "string"
          ]
         },
         "asOf": {
          "type": [
           "null",
           "string"
          ]
         },
         "percentile": {
          "type": [
           "null",
           "number"
          ]
         },
         "probability": {
          "type": [
           "null",
           "number"
          ]
         }
        }
       }
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "sourceUrl": {
       "type": [
        "null",
        "string"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "thresholds": {
       "type": [
        "null",
        "object"
       ],
       "properties": {
        "highAtLeast": {
         "type": [
          "null",
          "num
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/vulnerability-intelligence-epss-score-0d1c7638/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from vuln-intel.x402tookit.com](https://www.zero.xyz/host/vuln-intel.x402tookit.com/llms.txt)