Grades are a hygiene check, not a security guarantee.

MCP, MCP server

io.github.caelum29/calibre-mcp

Calibre ebook library for Claude: the calibre-mcp server (search, semantic search, content extraction, metadata curation — 17 tools) plus companion skills (guided setup, usage guide, calibre-distill, calibre-distill-topic).

Compatibility: Not stated.

Grade B

Minor issues only, no Medium or High. Worth a quick look at the findings below before installing.

Graded by PlugVetRubric v2

Not a guarantee. A hygiene check of the source at the commit shown, not a security audit.

NETWORK_NO_FIXED_HOST SECRETS_PATH_UNCONFIRMED

Why this grade

  • NETWORK_NO_FIXED_HOST Low

    Makes a network call whose host is not written as a fixed address.

    scripts/verify-merge-custom-columns.sh, line 65 curl -fsS "http://localhost:$PORT/ajax/library-info" >/dev/null 2>&1 && break

  • SECRETS_PATH_UNCONFIRMED Low

    The Secrets check reports a credential or environment file, but no quoted line shows a recognisable path.

    scripts/pack-mcpb.mjs, line 66 if (f === "manifest.json" && j.server?.mcp_config?.env) {

Any High, or two or more Medium findings, give D. One Medium gives C. Low findings or a security Note give B. Each code names a finding behind the letter.

Grades are a hygiene check of the source at the commit shown, on the date checked, not a security audit or a guarantee. The free directory grades are automated. Before release, a PlugVet engineer reviews every paid report and any grade we hold back, including all F grades, against the source code and the evidence we quote.

What was checked

Plain notes from the hygiene checks.

  • Permissions

    Pass

    No shell or command execution found, and no extra permission was declared.

  • Install and update

    Pass

    No install-time script found, and dependencies are pinned or absent.

  • Network

    Concern

    can reach a host that is not written as a fixed address.

    NETWORK_NO_FIXED_HOST

    scripts/verify-merge-custom-columns.sh, line 65

    curl -fsS "http://localhost:$PORT/ajax/library-info" >/dev/null 2>&1 && break

    scripts/verify-merge-custom-columns.sh, line 68

    LIB_ID="$(curl -fsS "http://localhost:$PORT/ajax/library-info" | python3 -c 'import json,sys; print(json.load(sys.stdin)["default_library"])')"

    src/calibre/content-server.ts, line 249

    const res = await fetch(url, { signal: controller.signal });

    Show more

    src/calibre/http.ts, line 30

    const res = await fetch(url, { signal: controller.signal });

    src/calibre/http.ts, line 100

    const res = await fetch(url, { signal: controller.signal });

    src/enrich/http.ts, line 21

    const res = await fetch(url, {

    src/tools/types.ts, line 68

    figures: FigureInventoryService; // figure inventory + pixel fetch (D-018)

    CHANGELOG.md, line 201

    count: no cover board, no row fetch (#67).

  • Secrets

    Concern

    reads a credential or environment file.

    SECRETS_PATH_UNCONFIRMED

    scripts/pack-mcpb.mjs, line 66

    if (f === "manifest.json" && j.server?.mcp_config?.env) {

  • Agent instructions

    Pass

    No instruction to ignore earlier instructions or to hide a step.

  • Obfuscation

    Pass

    No encoded or minified payload found.

  • Licence

    Pass

    A licence file is present (LICENSE).

  • Maintainer activity

    Pass

    The latest commit is within the last 365 days.

Get the full report on this tool, £49

Note

Hygiene check of commit d34ed480dcd4. can reach a host that is not written as a fixed address. reads a credential or environment file.

Date and source

Date checked:

View source

github.com

Commit graded: d34ed480dcd44969cc3c4e79a48cfe02eee182a7

This link goes to the original host. PlugVet does not host or check what you download from there, and installing it is your own decision and risk.

Read how this letter is chosen