Circl Vulnerability Lookup MCP server

@pipeworx/circl-vulnerability-lookup

Vulnerability records from CIRCL's Vulnerability-Lookup service, which resolves one id against several upstream feeds at once — MITRE CVE, NVD, GitHub Security Advisories, PySec and vendor CSAF advisories.

Part of Pipeworx — an MCP gateway connecting AI agents to 1679+ live data sources.

Tools

GHSA-, PYSEC- and vendor advisory ids alike. Returns a normalised summary (title, description, CVSS score/vector, affected products, references, dates) plus the untouched upstream record.

• circlvuln(id, includeraw?) — one vulnerability by id. Accepts CVE-,

against a CPE vendor/product pair, newest first, tagged with the feed each record came from.

• circlvulnsearch(vendor, product, limit?) — every vulnerability recorded

across every aggregated feed.

• circlvulnrecent(limit?) — the most recently published or updated records

Auth

Keyless.

Data sources

• — one record by id.
• — search.
• — recent records.

Operated by CIRCL (Computer Incident Response Center Luxembourg).

Traps

naively it reads as a successful empty record. circl_vuln throws a named miss instead.

• An unknown id answers {} with HTTP 200. That is a silent zero — parsed

/api/search/{vendor}/{product} and the recent feed is /api/last/{n}. /api/vulnerability/search/... and /api/vulnerability/last are both 404.

• The real paths are not the ones the names suggest. Search is

mixes all three:

• Records arrive in three different schemas, and one /api/last response

summarize() normalises the shared fields across all three; raw keeps the original. Do not assume containers.cna exists.

• CVE JSON 5.x — cveMetadata + containers.cna
• OSV — id / details / affected / severity
• CSAF — document / product_tree / vulnerabilities

containers.cna.metrics[], so the code scans the metric objects rather than reaching for a fixed path. OSV records carry only a vector string in severity[].score, with no numeric base score.

• CVSS lives under a version-specific key (cvssV31, cvssV40, …) inside

microsoft/windows_10, not Microsoft Windows 10.

• Vendor/product are matched against CPE strings, not marketing names — use

: 20 requests per minute anonymously, 40 with an X-API-KEY. It does send Retry-After (observed: 59) plus X-RateLimit-Limit/-Remaining/-Reset, and the 429 error here quotes it. This pack is keyless and stays inside the anonymous bucket — one tool call is one upstream request. If we ever need the higher tier, it is a header, not a rebuild.

• CIRCL rate-limits by source IP, and publishes the limits at

consecutive anonymous requests from one IP reported x-ratelimit-remaining of 0, then 19, then 3, and one URL kept 429-ing while the next id answered 200 instantly. So a 429 here frequently says nothing about your actual usage — circlJson() retries up to 3 times before surfacing it. Do not read a single 429 as "we are being throttled".

• The 429 is per backend worker, not global. Measured 2026-09-17: three

Related packs

nvd (NVD directly, platform-keyed) and osv (OSV.dev, open-source package advisories) cover single upstreams. This pack is the cross-feed id resolver: use it when you have an id and do not know which body published it.

Quick Start

Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):

{
  "mcpServers": {
    "circl-vulnerability-lookup": {
      "url": "https://gateway.pipeworx.io/circl-vulnerability-lookup/mcp"
    }
  }
}

What this endpoint actually serves

Shortened. The full README is on GitHub.