Matrix is experimental local-first software. Do not expose its HTTP or JSON-RPC listeners outside localhost unless you have configured API keys and understand the risk.

Only the latest tagged release receives security fixes.

Please report suspected vulnerabilities privately by opening a GitHub security advisory for this repository, or by contacting the maintainer through the repository owner profile if advisories are unavailable.

Do not publish exploit details until a fix or mitigation is available.

Never include provider tokens, Telegram bot tokens, API keys, vault databases, or logs containing prompts/secrets in public issues. Redact matrix-vault.db, configs/*.local.json, and runtime logs before sharing diagnostics.

Vault values use AES-GCM with the exact storage key as authenticated associated data (ENCV2). Moving a ciphertext to a different key fails authentication. The first writable open converts older ENCV1/plaintext records atomically, after checking space and verifying a private compact backup of all original records. A failed conversion leaves the original records unchanged. Read-only access never performs a conversion and never treats a retired envelope as plaintext.

The backup defaults to the vault directory. An operator may set the existing absolute directory MATRIX_VAULT_MIGRATION_BACKUP_DIR before upgrading to place it on another filesystem. Keep that backup and the original master key for rollback; an older binary must not be used against the upgraded vault.

Agent programs and explicitly authorized validators run with the operator's OS privileges. Child environments exclude daemon vault material, but file access by the same OS user is not a sandbox boundary. OS isolation is a separate policy.