HealthThread is a healthcare communication prototype with a deliberately isolated public synthetic demo. It is not a HIPAA-compliant clinical system and must not be used to provide emergency care, diagnose a condition, or store real patient data on the public Render deployment.

Security fixes are made on the default branch. The public demo contains only fictional Alex data. Local Personal mode is intended for one trusted developer machine unless production mode is placed behind the documented identity-aware proxy and configured with encryption and audit keys.

Use GitHub's Report a vulnerability private security-advisory flow for this repository. Include the affected route, reproduction steps, impact, and whether synthetic or real information was involved. Do not open a public issue containing credentials, OAuth tokens, health information, or a working exploit.

• Every health query and mutation is bound to a validated profile and context revision; request bodies cannot select an arbitrary owner.
• State-changing requests require same-origin context and a custom CSRF marker.
• Sessions use random tokens, hashed server-side state, and HttpOnly/SameSite cookies. HTTPS deployments also use Secure cookies.
• Public demo sessions receive isolated, in-memory synthetic data and cannot access Personal, document uploads, or real OAuth.
• OAuth uses PKCE, expiring state, one-time consumption, profile binding, and post-provider race checks.
• Optional AES-256-GCM envelope encryption protects records, documents, and provider tokens at rest. Production mode requires a 32-byte encryption key.
• Sensitive changes create PHI-free HMAC hash-chained audit records.
• Uploads are quarantined in memory until extension, magic-byte, active-content, XML-entity, and known-malware-fixture checks pass.
• AI output is schema validated, grounded, citation constrained, and rejected when it uses diagnostic language. Nothing becomes a health event without explicit confirmation.

• The built-in rate limiter is per Node process. Multi-instance production deployments require a shared store such as Redis.
• Built-in file inspection is defense in depth, not a replacement for a managed malware-scanning service.
• The CSP currently permits inline scripts/styles required by this Next.js build. A nonce-based policy is the planned production tightening.
• Production authentication expects signed assertions from an identity-aware proxy; HealthThread does not implement password storage.
• Application-layer encryption does not protect data already visible to a compromised running process.
• No compliance certification, BAA, clinical validation, disaster recovery, or formal penetration test has been completed.

See the threat model and the attack demonstration for details.