vuln-triage-mcp

Tells your AI agent which vulnerabilities to fix first, using OSV.dev, FIRST EPSS, and CISA KEV.

[badges: PyPI version, Python versions, license, tests]

Why this exists

Two or three sentences. CVSS alone ranks by severity, not by likelihood of exploitation. This server adds exploit probability (EPSS) and known exploitation (KEV), and shows its reasoning. Example: a CVSS 9.8 nobody exploits ranks below a CVSS 8.8 that is being exploited in the wild.

Quick start

Claude Code

claude mcp add vuln-triage -- uvx vuln-triage-mcp

Claude Desktop / other clients

JSON config snippet using uvx. Requires: Python 3.12+, no API keys.

Try it

Three example prompts and what to expect:

• "Which is most urgent: CVE-2021-44228, CVE-2023-4863, CVE-2019-10744?"
• "Is lodash 4.17.15 vulnerable? What should I upgrade to?"
• "Is CVE-XXXX actively exploited?"

Tools

How scoring works

• Formula: CVSS (base) x 40 + EPSS x 35 + KEV +25; KEV-listed floors at 80
• Buckets: see the table below
• Missing data: component omitted, named in reasoning, lowers confidence
• Link to docs/scoring-spec.md

unknown takes precedence over high, medium, and low; it never applies to a KEV-listed vulnerability.

Reliability and limits

• Partial results: if EPSS or KEV fails, the result names the missing source
• Truncation: truncated, found_count vs returned_count, ranking_note
• Stale KEV cache: stale and catalog_fetched_at
• Timeouts and retry policy (one line)
• Package queries return at most 50 advisories, sorted by severity

Security

• Advisory text is untrusted third-party content (prompt injection vector): sanitized, length-capped, returned under untrusted_text, and flagged to the model in the server instructions
• Input validation on all IDs and ecosystems
• No credentials required or stored; read-only calls to three public APIs
• Reporting vulnerabilities in this project: SECURITY.md or email

Evaluation

Golden set: 17 entries (16 CVEs, 1 GHSA) with expected buckets, confidence, and ordering, recorded 10/21/2026. Result: 17/17 match on the recorded fixtures (uv run pytest tests/test_golden.py), and 17/17 against the live APIs on 10/21/2026 (uv run pytest -m live tests/test_golden.py). EPSS drifts daily, so the live run can diverge over time; re-record the fixtures with uv run python scripts/record_golden_fixtures.py when the golden set or scoring spec changes.

Data sources and attribution

OSV.dev, FIRST EPSS (cite per their usage terms), CISA KEV. Not affiliated with any of them.

Development

uv sync, uv run pytest, running the Inspector, live-test marker.

License

MIT