MeshStar is a security-focused project: it carries people's private messages over a public radio band. We take reports seriously and we design to make them rare.

Please report security issues privately first, not in a public issue:

• Open a private advisory on GitHub (Security tab, "Report a vulnerability"), or
• Email the maintainer listed on the GitHub profile.

Include what you found, how to reproduce it, and the impact you see. We aim to acknowledge within a few days and to agree a disclosure timeline with you. We credit reporters who want it.

• Every byte from the air or BLE is untrusted. Validation lives in Packet::decode and in each codec's decode, which return Err and never panic. Each new codec ships with a "random garbage does not panic" test.
• Continuous fuzzing. The decoders are fuzzed with libFuzzer (see crates/meshstar-core/fuzz/): a short smoke run on every CI build and a longer scheduled run nightly. Reproducers from any crash are uploaded as artifacts.
• Audited cryptography primitives. Signatures, key exchange and AEAD use vetted crates (ed25519-dalek, x25519-dalek, chacha20poly1305, sha2, hmac, aes, ctr, ccm). The Noise XX state machine is implemented to the specification in crypto/noise.rs; its primitives are pinned by PROTOCOL_NAME_* and are not changed without updating those.
• End-to-end by default. MeshStar unicast runs inside Noise XX sessions with mutual authentication and forward secrecy. Relays forward but cannot read.
• Honest labelling. Foreign networks (Meshtastic, MeshCore) use shared channel keys. MeshStar never presents a channel key as end-to-end encryption; each message carries its real security level.

See docs/THREAT_MODEL.md for the full model and its assumptions, and docs/CRYPTO_REVIEW.md for a guide to reviewing the handshake and transport cryptography (what is standard Noise XX, what is MeshStar-specific, and how it is tested).

In scope: the protocol, the decoders, the cryptography, the companion protocol, and the firmware. Out of scope: physical attacks on a device you hand to someone, and the inherent fact that LoRa transmissions are detectable by radio.

MeshStar is pre-1.0 and moves fast. Security fixes land on main; please test against main before reporting.