The good news is that if one is traveling with a guitar for personal use (meaning you aren’t shipping) there is a 10kg threshold before CITES applies (meaning the guitar must contain more than 10kg of a CITES-protected wood). But... The bad news is that the 10kg exemption does NOT apply to Brazilian rosewood. So, in practice, whether the 10kg exemption will apply to your bass on any particular day depends upon whether your particular customs inspector can tell the difference between Brazilian rosewood and the other rosewood species. No offense, but the truth is most bass players can’t tell the difference, so trusting that any given customs inspector will be able to do so is a pretty risky strategy. That’s why the safest bet is to get a CITES musical instrument passport, as described elsewhere in this thread.