Please do NOT open a public issue for a security problem. Report it privately via GitHub's "Report a vulnerability" (Security tab of this repository), or by email to florian.mousseau@gmail.com. You will get an acknowledgement within a few days; a fix and coordinated disclosure follow as fast as severity demands.

selfstore's security promises are documented in the README ("Security model"): AES-256-GCM over an Argon2id-derived key for backups, GCM-authenticated ciphertext and parameters, cleartext cosmetic header fields that are NOT authenticated, a zip-bomb guard, at-rest cache sealing under a non-extractable device key, and a downgrade guard (UNEXPECTEDLY_UNENCRYPTED). Anything that breaks one of those promises is in scope - including practical attacks below the stated KDF cost, silent plaintext fallbacks, or authentication bypasses.

Out of scope: attacks requiring code execution in the same origin (an XSS can read whatever the app can), and the platform's own limits (JavaScript strings cannot be zeroized).

Pre-1.0, only the latest published minor receives fixes.