Please do not open a public issue or discussion for a suspected vulnerability.

Use the repository's Security tab on GitHub and choose Report a vulnerability to send a private report to the maintainers. If that option is not available, open a public issue that says only that you have a security report and asks for a private way to send it. Leave the details out of the issue.

Include the hk version (hk version), your operating system, and the steps to reproduce.

hk runs the commands in a project's hk.pkl, so running hk in a repository you do not trust runs that repository's code. That is how hk works, not a vulnerability by itself. Security model describes what hk executes, what Pkl evaluation can read and fetch, how global hooks reach every repository, and what --safe does and does not guarantee. Read it before reporting behavior it already documents.