mcp-cve-watch

Continuous CVE intelligence for your MCP servers' runtime dependencies.

MCP servers run real code — npm packages, PyPI packages, system daemons with network access. A vulnerability in one of those dependencies is a vulnerability in everything that server can touch. Public CVE disclosures against MCP ecosystem packages are rising, and most MCP users never check: the server was installed once, npx cached it, and nobody looked at it again.

mcp-cve-watch subscribes you to that feed. Point it at the dependency manifests your MCP servers run on, and watch checks OSV.dev (which aggregates CVE and GitHub Advisory data across PyPI, npm, and more) for every pinned dependency. The first run records a baseline; every later run alerts only on new CVEs — with severity mapped from CVSS scores — so it works as a quiet cron job or a CI gate.

Zero dependencies. Python standard library only.

Install

pip install mcp-cve-watch
# or with pipx:
pipx install mcp-cve-watch

Requires Python 3.9+. No other packages.

Usage

Check your MCP servers' dependencies — pass the manifest files the servers run on (requirements.txt pins for Python-based servers, package.json for Node-based ones):

$ mcp-cve-watch watch ./mcp-servers/requirements.txt ./mcp-servers/package.json
checked 14 pinned dependencies at 2026-10-11 08:52 UTC

*** 2 NEW CVE(s) since last check ***

SEVERITY  SCORE  ID              PACKAGE     VERSION  SUMMARY
--------  -----  --------------  ----------  -------  ----------------------------------------
CRITICAL  9.8    CVE-2024-0001   some-lib    1.2.3    Remote code execution via crafted input...
HIGH      7.5    CVE-2024-0002   other-lib   4.5.6    Denial of service in parser...

Run it again tomorrow: if nothing new appeared, it just says so.

$ mcp-cve-watch watch ./mcp-servers/requirements.txt
checked 8 pinned dependencies at 2026-10-12 09:00 UTC
no new CVEs since last check

Use it as a CI gate — fail the build when a new high-or-worse CVE shows up:

mcp-cve-watch watch requirements.txt --fail-on high   # exits 3 on new HIGH/CRITICAL

Print the full report of everything the last run found:

$ mcp-cve-watch report --format markdown
mcp-cve-watch report (last check: 2026-10-11T08:52:11+00:00) — 2 finding(s)

| Severity | Score | ID | Package | Version | Summary |
|---|---|---|---|---|---|
| critical | 9.8 | CVE-2024-0001 | some-lib | 1.2.3 | Remote code execution via crafted input... |

Options worth knowing:

• --severity high — only record HIGH and above (default is low)
• --include-dev — also scan devDependencies in package.json
• --format json — machine-readable output for both watch alerts and report
• --min-severity on report — filter the printed report
• State lives in ~/.config/mcp-cve-watch/state.json (MCP_CVE_WATCH_DIR or --state-dir overrides it)

Cron example — a daily check that emails you only when something is new:

0 9 * * * mcp-cve-watch watch ~/mcp-servers/requirements.txt --fail-on high --severity medium

Differentiation

• vs mcp-audit — mcp-audit is a point-in-time runtime audit: it handshakes each MCP server once and reports what it sees right now (tool counts, schema cost, failures). mcp-cve-watch is a continuous vulnerability-intelligence subscription: it keeps a baseline of every known CVE on your servers' dependencies and alerts only on what's new since the last check. Run the audit when you install a server; run the watch every day after.
• vs Dependabot / Renovate — those watch the dependencies of a GitHub repository. mcp-cve-watch watches the dependencies of your MCP servers at runtime — the pinned npx/uvx packages actually executing on your machine, which often don't live in any repository Dependabot can see.

How it works

1. Parses each manifest into pinned (name, version, ecosystem) triples (PyPI from requirements.txt, npm from package.json).
2. Sends one batched query to the OSV.dev API — no API key needed.
3. Maps CVSS scores to severity (≥9.0 critical, ≥7.0 high, ≥4.0 medium).
4. Diffs against the previous run's state and alerts only on new findings.

Only pinned versions (==, exact npm versions) can be checked against a CVE feed — unpinned lines are skipped with a warning. Pin your MCP server deps.

License

MIT — see LICENSE.