In Germany, Mein Kampf is banned except for educational purposes, eg in history class.
Strictly speaking this is incorrect, although the situation is somewhat complicated. There are laws that can be and were used to limit its redistribution (mainly the rule against anti-constitutional propaganda), but there are dissenting judgements saying original prints from before the end of WW2 cannot fall under this, since they are pre-constitutional. One particular reprint from 2018 has been classified as "liable to corrupt the young", but to my knowledge this only means it cannot be publicly advertised.
What is interesting though is how distribution and reprinting was prevented historically, which is copyright. As Hitlers legal heir the state of Bavaria held the copyright until it expired in 2015 and simply didn't grant license to anything except versions with scholarly commentary. But technically since then anybody can print and distribute new copies of the book. If this violates any law will then be determined on a case-by-case basis after the fact.