Hexis Mcp Guard

Security scanner for MCP (Model Context Protocol) servers.

Install

pip install hexis-mcp-guard

Or from source:

git clone https://github.com/Noumenon-ai/hexis-mcp-guard.git
cd hexis-mcp-guard
pip install -e ".[dev]"

Usage

hexis scan ./my-server/
hexis scan --format sarif -o results.sarif ./server/
hexis scan --format json ./server/
hexis scan --url http://localhost:8080 --dynamic
hexis scan ./server/ --ai
hexis scan ./server/ --ci --fail-on high
hexis scan ./server/ --baseline .hexis-baseline.json
hexis rules

Features

• 14 security rules (SSRF, shell injection, auth, prompt injection, resource exposure, transport)
• Static analysis + dynamic probing
• SARIF 2.1.0 output for GitHub Security tab
• JSON + rich terminal output
• CI/CD ready (exit codes)
• Optional AI reasoning (Claude)

Rules

Rule	Severity	Category	Description
HEXIS-AUTH-001	HIGH	auth	No authentication on transport
HEXIS-AUTH-002	HIGH	auth	Missing authorization checks on sensitive tools
HEXIS-CMD-001	CRITICAL	shell_injection	subprocess/exec with user input
HEXIS-CMD-002	CRITICAL	shell_injection	shell=True with string interpolation
HEXIS-CMD-003	CRITICAL	shell_injection	eval/exec on tool arguments
HEXIS-PI-001	HIGH	prompt_injection	Tool description contains injection patterns
HEXIS-PI-002	MEDIUM	prompt_injection	Return values flow unsanitized to LLM context
HEXIS-PI-003	HIGH	prompt_injection	Tool poisoning via hidden instructions in descriptions
HEXIS-RES-001	HIGH	resource_exposure	Unrestricted file system access
HEXIS-RES-002	HIGH	resource_exposure	SQL query tool without parameterization
HEXIS-SSRF-001	HIGH	ssrf	URL parameter in tool inputSchema without validation
HEXIS-SSRF-002	CRITICAL	ssrf	Server-side fetch with user-controlled URL
HEXIS-SSRF-003	CRITICAL	ssrf	Internal IP/metadata endpoint accessible
HEXIS-TLS-001	MEDIUM	transport	Plaintext HTTP transport in production

CI/CD Integration

GitHub Actions

- name: MCP Security Scan
  run: |
    pip install hexis-mcp-guard
    hexis scan ./src --format sarif --output results.sarif --ci --fail-on high

- name: Upload SARIF
  uses: github/codeql-action/upload-sarif@v3
  with:
    sarif_file: results.sarif

Exit Codes

Code	Meaning
0	No HIGH/CRITICAL findings
1	HIGH findings detected
2	CRITICAL findings detected

License

MIT

Built by Noumenon