Hugging Face Hub MCP

https://huggingface.co/mcp

github.com/huggingface/hf-mcp-server

Score

A96

Findings

Tools

Last scan

2026-09-19

Severity breakdown

Critical0

High0

Medium2

Low0

Info0

Worst finding

Tool `hub_repo_search` accepts unconstrained string input

· hub_repo_search

The following string parameter(s) have no `maxLength` constraint: `author`, `query`. Unbounded strings let an attacker stuff arbitrary payloads through the tool, including indirect-injection content.

fix: Add a `maxLength` to each string property, or constrain with an `enum` or `pattern`. Most legitimate tool inputs fit under a few hundred bytes.

All 2 findings

medium
Tool `hub_repo_search` accepts unconstrained string input· hub_repo_searchunconstrained input
The following string parameter(s) have no `maxLength` constraint: `author`, `query`. Unbounded strings let an attacker stuff arbitrary payloads through the tool, including indirect-injection content.
fix: Add a `maxLength` to each string property, or constrain with an `enum` or `pattern`. Most legitimate tool inputs fit under a few hundred bytes.
medium
Tool `hub_repo_details` accepts unconstrained string input· hub_repo_detailsunconstrained input
The following string parameter(s) have no `maxLength` constraint: `config`, `split`. Unbounded strings let an attacker stuff arbitrary payloads through the tool, including indirect-injection content.
fix: Add a `maxLength` to each string property, or constrain with an `enum` or `pattern`. Most legitimate tool inputs fit under a few hundred bytes.

Reproduce this

Every finding above comes from a public, deterministic rule engine — no LLM in the decision path, same input always the same output. You can run it against this server yourself and get byte-identical results:

curl -fsSL capframe.ai/install | sh
capframe find ./your-mcp-config.json --out findings.json

Five-step quickstart if you want the whole Find → Bind → Guard loop. If you'd rather have someone read your real tool definitions rather than the advertised surface — including the ones this public scan can't reach — that's the Agent Security Audit.

How this was scored

Source http — live HTTP MCP endpoint, classified against every rule. Findings are emitted by the public capframe.findings.v1 schema. Score = 100 − (10·Critical + 4·High + 2·Medium + 1·Low), clamped to [0, 100].

Disagree with a finding? Open an issue.