Leo Health handles sensitive personal health data. This document describes the security model, known limitations, how to verify privacy claims, and how to report vulnerabilities.

Leo Health does not intentionally transmit data to external services. The application only binds to localhost and performs no outbound network requests in the current codebase.

Leo Health is designed so that all health data remains local to your machine.

Primary platform: macOS Other platforms: Best effort (Linux parsing works; macOS-specific features such as notifications require osascript)

• Network exfiltration — dashboard binds to 127.0.0.1 (loopback only), no outbound connections
• Browser caching of health data — Cache-Control: no-store on all responses
• MIME sniffing attacks — X-Content-Type-Options: nosniff on all responses
• Script injection — Content-Security-Policy on HTML responses: default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'
• SQL injection via identifiers — explicit table/column allowlist in _insert_many()
• AppleScript injection via filenames — input sanitized before osascript calls
• Weak file deduplication — SHA-256 full-file hashing (not MD5 partial reads)
• World-readable health data — DB directory created with 0700 permissions

• Local machine access — anyone with access to your Mac can read ~/.leo-health/leo.db. Use macOS FileVault for full disk encryption.
• No authentication — the dashboard has no login. Designed for single-user desktop use only.
• Local process access — any process running on the same machine can access the local dashboard. Leo Health assumes the local system is trusted.
• Multi-user environments — not designed or tested for shared machines.
• Browser extensions and DNS rebinding — advanced local attack vectors exist on any localhost server. Leo Health does not mitigate these.

The codebase intentionally avoids outbound network libraries. You can verify by searching for common networking modules:

grep -r "import urllib\|import http\|import requests\|import socket\|http.client\|urllib.request" .

You will see three results, all in leo_health/dashboard.py — these are Python stdlib imports used exclusively to run a local web server on your own machine (localhost only).

Note: This grep covers the most common patterns but does not catch dynamic imports or future contributions. Review the full source for complete assurance.

Leo Health is implemented using the Python standard library only and has zero runtime third-party dependencies. This significantly reduces supply chain risk — there are no third-party packages to audit, pin, or patch.

Installation via pip install -e . uses setuptools and wheel for build only. These are not runtime dependencies.

No data is synced to the cloud, shared with third parties, or transmitted anywhere.

This project is under active development. Always use the latest version from main. Security fixes will be released as quickly as possible after validation.

If you discover a security vulnerability, please do not open a public GitHub issue.

Report it via:

• GitHub private vulnerability reporting (Security tab → "Report a vulnerability")
• Or contact the maintainer directly via GitHub profile

Please include:

• Description of the vulnerability
• Steps to reproduce
• Potential impact
• Suggested fix (if any)

You will receive a response within 72 hours. We take all reports seriously given the sensitive nature of health data.