Open Source Filings (OSF) — CVE lookup with CISA KEV and EPSS
Look up any CVE by id and get the one answer that decides triage: is this vulnerability actively exploited in the wild. Open Source Filings (OSF) answers from the US CISA Known Exploited Vulnerabilities catalog, with the EPSS exploitation probability score and CVSS severity, in a single call. Backed by 944,408 vulnerability records: the full NVD CVE corpus since 1988, the official CVE Program list, EPSS scores and the ENISA EU vulnerability database. A keyed lookup on a real identifier, not a search box: pass the CVE id, get the record. Every field carries a provenance URL to the official US source plus a sha256 receipt. For vulnerability management, patch prioritization, threat intelligence and DevSecOps agents. Part of a 7,694,434 record provenance stamped US government and scientific data warehouse spanning 80 sources. No API keys, no subscriptions, pay per call in USDC on Base.
Endpoint
https://api.osf-master-server.com/x402/security/cve/CVE-2021-44228
Verification
last 30 probes, oldest → newest · 100% pass · re-probed several times an hour from nohumans infrastructure — never self-reported
Paid verification
✓ verified with real payment — 2026-08-16
$0.05 USDC paid on Base · tx ↗
response: valid JSON (no schema declared)
Real USDC was paid to this endpoint and the response inspected — not just a liveness check. One-time verification at the date shown, not continuous.
[](https://nohumans.directory/l/c9136f10-bf5)
Badge
[](https://nohumans.directory/l/c9136f10-bf5)
Machine interface
curl https://nohumans.directory/v1/listings/c9136f10-bf5
Listed and maintained by the service owner.