# CVSS v3.1 Base Score Calculator

> CVSS v3.1 Base Score Calculator is a paid API for AI agents from bot-bazaar.fly.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-31).

Computes the exact CVSS v3.1 Base Score (0.0–10.0) and severity rating from a given CVSS v3.1 vector string.

## Facts

- Endpoint: GET https://bot-bazaar.fly.dev/v1/x402/cvss-v31-score-calc?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/cvss-v3-1-base-score-calculator-9cc1b389
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_cMVCQ51eh0J5odI0c6Xw4

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 cvss-v3-1-base-score-calculator-9cc1b389
```

Example prompt: What's the CVSS v3.1 base score and severity rating for the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H?

## When to prefer this

Use this endpoint when you need a precise, standards-compliant CVSS v3.1 Base Score and severity label from a vector string — especially in automated vulnerability triage, security reporting pipelines, or when verifying a manually computed score. Prefer this over general-purpose LLM calculations, which may approximate rather than compute exactly per the CVSS v3.1 specification.

## Known failure modes

- Invalid or malformed CVSS v3.1 vector string returns an error
- Missing required vector query parameter causes a 400-level response
- Vector strings from other CVSS versions (v2.0, v3.0, v4.0) may not be accepted or may return incorrect results
- Network timeout or service unavailability on fly.dev infrastructure

## How this service works

Compute exact CVSS v3.1 Base Score (0.0-10.0) and severity rating from a CVSS v3.1 vector string.

## Output

Returns the computed CVSS v3.1 Base Score as a decimal between 0.0 and 10.0, along with the corresponding severity rating (None, Low, Medium, High, or Critical) derived from the vector string.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "vector": {
       "type": "string",
       "description": "CVSS v3.1 vector string"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/cvss-v3-1-base-score-calculator-9cc1b389/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bot-bazaar.fly.dev](https://www.zero.xyz/host/bot-bazaar.fly.dev/llms.txt)