Only the latest release on PyPI is supported. There's no long-term-support branch; upgrade to get a fix.

Please use GitHub's private vulnerability reporting instead of opening a public issue. That starts a private conversation with the maintainer so a fix can land before the details are public.

You should get a response within a few days. This is a solo-maintained open-source project without a dedicated security team, so please be patient.

Two things are already true by design, documented here explicitly rather than left as a surprise:

• FASTDOCPARSE_PLUGINS executes arbitrary Python at CLI startup. Setting this environment variable imports and runs whatever module(s) it names, with no sandboxing, the same trust model as PYTHONSTARTUP or DJANGO_SETTINGS_MODULE. This is fine for pointing it at your own plugin on your own machine. Never let this variable be set from an untrusted source, e.g. a request parameter in a hosted service built on top of this CLI. See the docstring on _load_plugins() in src/fastdocparse/cli.py.
• The ReDoS guard on user-supplied regex patterns doesn't always run. grounding.py's _regex_matches_with_timeout relies on SIGALRM, which doesn't exist on Windows, so a pathological pattern in a schema (yours or an LLM-generated one) has no timeout protection there, and it's also bypassed when extraction runs off the main thread, even on platforms that do have SIGALRM, since signal-based timeouts only work on the main thread. If you call this library from a background thread (e.g. a web server handling requests concurrently), or you're on Windows, treat this guard as absent and validate patterns yourself before accepting schemas from an untrusted source. This is a known, accepted gap (see issue #28), not a secret one.

If you find something beyond these two, please report it privately rather than assuming it's already known.