Query Doctor is a read-only analysis tool. It never applies a rewrite; it reports one.

Open a private security advisory on the GitHub repository (Security → Report a vulnerability), or email the maintainer listed on the GitHub profile. Please do not file a public issue for an exploitable bug. Expect a first reply within a few days.

• Read-only SQL. src/guard/sqlGuard.ts accepts one statement and refuses writes, DDL, multiple statements and external paths, for the original and every candidate. The DuckDB sample engine also locks external access.
• Credentials are read from the environment or ~/.config/querydoc/*.env, never from the tree. .env.example has empty values. A gitleaks workflow is defined (.github/workflows/gitleaks.yml) but has not run on GitHub; a local full-history scan found no leaks.
• Live-mode API. Binds 127.0.0.1 by default; answers only on localhost, an IP literal or QUERYDOC_ALLOWED_HOSTS names (DNS-rebinding guard); cross-origin writes are refused. The Docker image sets HOST=0.0.0.0 and runs sample mode.
• Dependencies. npm audit --omit=dev reports 0 vulnerabilities at the last release commit.

See FAILURE_MODES.md. The API has no authentication: run live mode on a trusted machine only.