# fittings EPSS Score Lookup

> fittings EPSS Score Lookup is a paid API for AI agents from fittings.sh, paid per call via x402, $0.00398/call, status unknown (last checked 2026-10-10).

Returns the FIRST.org EPSS probability and percentile for one or more CVEs, indicating the modeled likelihood of exploitation within the next 30 days.

## Facts

- Endpoint: GET https://fittings.sh/v1/epss/score?utm_source=zero.xyz
- Price: $0.00398/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fittings-epss-score-lookup-c3632f06
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Bh5vjabdqSh3RdrefQj6-

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 fittings-epss-score-lookup-c3632f06
```

Example prompt: What's the EPSS exploitation probability and percentile for CVE-2021-44228 and CVE-2023-44487 — I want to know how likely each is to be exploited in the next 30 days?

## When to prefer this

Use this endpoint when you need fast, authoritative EPSS exploitation probability scores from FIRST.org for one or more CVEs — especially when prioritizing patch management or vulnerability triage by exploitation likelihood rather than CVSS severity alone. Prefer this over manual FIRST.org lookups or CVSS-only scoring when you want a data-driven, quantitative exploitation risk signal.

## Known failure modes

- Invalid or non-existent CVE ID returns an error or empty result
- More than 50 CVEs submitted in a single request may be rejected
- Malformed CVE format (e.g. missing 'CVE-' prefix) may yield no results
- Network or upstream FIRST.org data unavailability could cause timeouts
- Very new CVEs may not yet have an EPSS score assigned

## How this service works

The FIRST.org EPSS probability and percentile for one or more CVEs: the modelled chance each is exploited in the next 30 days.

## Output

Returns, for each queried CVE, its EPSS probability (a float between 0 and 1 representing the modeled chance of exploitation in the next 30 days) and its percentile rank relative to all scored CVEs, as sourced from the FIRST.org EPSS model.

## 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": [
      "cve"
     ],
     "properties": {
      "cve": {
       "type": "string",
       "description": "One CVE id, or up to 50 comma-separated"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fittings-epss-score-lookup-c3632f06/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fittings.sh](https://www.zero.xyz/host/fittings.sh/llms.txt)