SimulatoKit is a numerical library with no network code. The most likely security-relevant problems are crashes or memory errors on malformed input (for example, a malformed CIF file given to the example executable).
Please report it privately through GitHub's "Report a vulnerability" button on the repository's Security tab rather than in a public issue. Include the version, the input that triggers the problem and what you observed. We will acknowledge a report as soon as we can.
Fixes are made on the latest released version.