If you found a bug or thought of a nice way to improve Kactus, head over GitHub, that's where we keep track of what is happening: https://github.com/kactus-io/kactus. Check if someone already had the same bug/idea or open a new issue.
If you found a vulnerability in the project, please write privately to email@example.com. Thanks!
If you just want to chat, my DM are open: @mathieudutour :)