io.github.youdotcom-oss/mcp

What we checked

Six static checks, weighted by risk. Every result reflects only what could be observed in the published package and repository — never intent.

• Injection surface

  unscannable25% of grade

  Tool descriptions/manifest scanned for instruction-injection patterns (imperatives at the model, hidden text, 'ignore previous', data-exfil URLs).

  No tool descriptions, server instructions, prompts, or resources were fetched; nothing to scan for injection.

• Supply chain

  warn25% of grade

  Package provenance: namespace verification, repo linkage, maintainer count, account age, postinstall scripts, typosquat distance.

  package name "@youdotcom-oss/mcp" is edit-distance 2 from popular package "yup" (typosquat candidate); dependency "hono" is edit-distance 2 from popular package "pino" (typosquat candidate); dependency "@hono/mcp" is edit-distance 2 from popular package "yup" (typosquat candidate)

• Credential hygiene

  pass15% of grade

  How the server takes secrets (env vs plaintext config vs hardcoded); secrets appearing in tool schemas.

  Reads secrets from the environment (e.g. src/contents/contents.utils.ts) — the recommended intake shape. PASS = no static red flag; static analysis cannot prove the code honors env-based secret handling at runtime.

• Permission scope

  warn15% of grade

  Declared tools vs. breadth (filesystem, network, exec); flags shell-exec and unbounded filesystem access.

  discloses broad/destructive filesystem access: src/contents/tests/contents.utils.spec.ts: path traversal ('../') combined with file access discloses broad/destructive filesystem access: src/contents/contents.utils.ts: path traversal ('../') combined with file access discloses broad/destructive filesystem access: src/express/tests/express.utils.spec.ts: path traversal ('../') combined with file access discloses broad/destructive filesystem access: src/express/express.utils.ts: path traversal ('../') combined with file access discloses broad/destructive filesystem access: src/tests/http.spec.ts: path traversal ('../') combined with file access discloses broad/destructive filesystem access: src/http.ts: path traversal ('../') combined with file access discloses broad/destructive filesystem access: src/search/tests/search.utils.spec.ts: path traversal ('../') combined with file access discloses broad/destructive filesystem access: src/tests/tool.spec.ts: path traversal ('../') combined with file access Capability DISCLOSURE, not a verdict: static analysis sees the primitive is present and reachable, not whether its use is attacker-controlled.

• Version behavior

  unscannable10% of grade

  Diff of tool definitions between versions; new permissions or changed descriptions in a patch release (the postmark-mcp class).

  no prior version to diff (first sight of io.github.youdotcom-oss/[email protected]); version-drift / rug-pull cannot be evaluated. Cold-start risk is covered by point-in-time checks (injection_surface, supply_chain, credential_hygiene), not here.

• Transport config

  warn10% of grade

  Remote servers: TLS and auth mode (none/token/OAuth). Local servers: whether the manifest indicates it phones home.

  manifest/source references tracking behavior — disclosure