Report suspected vulnerabilities through the repository's private vulnerability reporting form. Do not open a public issue containing device keys, captured memory, exploit details, or production endpoint credentials.

• Admin and metrics listeners bind to loopback by default.
• Remote Trace destinations must use HTTPS.
• Admin and ingest bearer tokens are independent.
• Authorization uses constant-time comparison.
• Redirects are rejected so credentials are never forwarded to a different host.
• Event and artifact objects use restrictive permissions and content hashes.
• HTTP body size, header size, timeouts, connection count, and concurrent ingest are bounded.
• Unknown YAML fields are rejected.
• Raw event payloads and secrets are never included in normal logs.

Relay validates LEP envelope integrity with CRC-32/IEEE and authenticity with HMAC-SHA-256 or XChaCha20-Poly1305 before persisting or forwarding. Keys are derived via HKDF-SHA-256 with domain separation. Nonces are checked for repetition. Replay windows are enforced per key_id. Raw event payloads are stored on disk with restrictive permissions; content hashes enable tamper detection on export.

The older HMAC-SHA-256 envelope format remains supported for verification only unless allow_legacy_hmac is explicitly enabled by the operator.

Relay treats devices, imported files, remote destinations, artifacts, and network clients as untrusted. Operators must:

• Protect the data directory with restrictive file permissions.
• Use TLS outside loopback for all remote communication.
• Rotate admin and ingest tokens independently.
• Apply privacy filters and redaction policies before forwarding memory dumps to third-party destinations.
• Review the compatibility matrix in docs/compatibility-matrix.md before enabling draft features in production.

• Provision a unique random 256-bit master key per device fleet. Do not derive it from a serial number, MAC address, password, or firmware secret.
• Register a cryptographically secure random provider before enabling envelope or at-rest encryption.
• Increment key_id on every key rotation and retain old keys server-side only for the required migration window.
• Use verified TLS in addition to envelope encryption. Never set peer verification to optional in production.

Relay includes race-detector tests, fuzz targets for LEP parsers, sanitizer runs, and durability verification. These checks do not replace an independent security review, side-channel evaluation on the target platform, secure provisioning review, or product certification. Do not claim FIPS, Common Criteria, or PSA certification based on this repository alone.