You can review existing issues (including bugs and new features) or file a new bug via the issue list.
If you are not sure if something is a bug, or need a hand, please join the discussion.
What constitutes a bug?
The goal of jsoup is that is will sensibly parse any real-world HTML page into effectively the same parse tree that a modern browser would.
If you find a page that jsoup doesn't parse correctly, or if it doesn't behave as the documentation says it will, then that's a bug, and your assistance by way of filing it is welcomed.
For the fastest fix, please supply your code and the input HTML that triggers the issue.