Cve is based on https://csrc.nist.gov/schema/nvd/api/2.0/cve_api_json_2.0.schema (see `cve_item`).

CvssDataV20 is based on https://csrc.nist.gov/schema/nvd/api/2.0/external/cvss-v2.0.json.

CvssDataV30 is based on https://csrc.nist.gov/schema/nvd/api/2.0/external/cvss-v3.0.json v3.0 and v3.1 have only one difference: `patterns` for `vectorString`.

CvssDataV40 is based on https://csrc.nist.gov/schema/nvd/api/2.0/external/cvss-v4.0.json.

CvssMetricV3 is based on https://csrc.nist.gov/schema/nvd/api/2.0/cve_api_json_2.0.schema.

CvssMetricV40 is based on https://csrc.nist.gov/schema/nvd/api/2.0/cve_api_json_2.0.schema.