memlawb is security software — a zero-knowledge memory backend. We take reports seriously and appreciate responsible disclosure.

Do not open a public issue, PR, or discussion for a security vulnerability.

Report privately via GitHub Private Vulnerability Reporting:

1. Go to the repository's Security tab.
2. Click Report a vulnerability (under "Advisories").
3. Describe the issue, the impact, and a reproduction if you have one.

This opens a private advisory only you and the maintainers can see. We aim to acknowledge within 72 hours and to keep you updated as we triage, fix, and coordinate disclosure. With your agreement we'll credit you in the advisory.

If you cannot use GitHub advisories, note that in any channel you can reach the maintainers and we'll arrange a private path.

memlawb is pre-1.0 and ships from main. Security fixes land on the latest 0.x minor and are released promptly. Older 0.x lines are not maintained — please track the latest release.

memlawb's core guarantee is that the server is crypto-blind: clients encrypt every entry before upload (AES-256-GCM, key derived from a passphrase that never leaves the client), so the server stores and serves only ciphertext.

The server can see: namespace ids, entry keys (paths), ciphertext blobs, ciphertext byte sizes and hashes, and timestamps. The server cannot see: memory plaintext, your passphrase, or the derived key.

We're especially interested in reports that break these properties:

• Any way the server could recover plaintext, the passphrase, or a data key.
• Cross-tenant access — one owner reading or writing another's namespace (namespace authorization is in src/auth.ts).
• Crypto weaknesses — nonce reuse beyond the documented deterministic design, AEAD/AAD binding bypass, key-derivation issues (client/crypto.ts).
• Path traversal via namespace or entry keys (src/namespace.ts).
• Quota / rate-limit bypass enabling resource exhaustion (src/quota.ts, src/ratelimit.ts).
• Secret-scanner bypasses that let obvious credentials upload unflagged (client/secretscan.ts) — defense-in-depth, but still worth reporting.

• No passphrase recovery. Zero-knowledge means if you lose your passphrase, the host cannot recover your data. This is by design.
• Byte-identical entries are detectable. The deterministic nonce that enables delta sync reveals whether two ciphertext entries are identical. Documented trade-off in client/crypto.ts.
• Metadata is visible to the host (namespace ids, entry keys, sizes, timestamps) — see scope above. A future tier may hash entry keys.
• Single-instance hosted beta. The hosted deployment runs one instance on purpose; in-process locks/limits assume that (see PLAN.md §7). Self-hosters should not run multiple instances against shared storage until the Postgres index lands.

Thank you for helping keep memlawb and its users safe.