Do not open a public issue. Report it privately through GitHub security advisories. Include the version, the steps to reproduce, and the impact.

Only the latest release gets fixes.

The server stores ciphertext only. It cannot read note content, file names, or paths.

• Vault data is encrypted on the device with XChaCha20-Poly1305. The keys come from a random vault secret through Argon2id and HKDF. The vault secret never leaves paired devices unencrypted.
• Blob ids are keyed BLAKE3 hashes, so the server cannot match files against known content.
• Each device has an Ed25519 key. It signs every API request and the WebSocket handshake. Revoked devices are rejected.
• A new device gets the vault secret through an X25519 exchange. Approve it only when the six-digit safety code matches on both devices.
• The admin API answers loopback connections only.

• The server sees metadata: device ids, op count and timing, and blob and op sizes.
• Anyone with access to a paired device can read the vault. Local sync state is not encrypted at rest.
• On platforms without Obsidian SecretStorage, the device key and vault secret are stored in the plugin data file.
• If you lose every paired device, the vault cannot be recovered.
• Use TLS, directly or through a reverse proxy, for any server that is not on localhost.