Generally jailbreaks can be saved across kindle updates, but you should update to the latest version of the jailbreak and hotfix first. Some extensions might re

Generally jailbreaks can be saved across kindle updates, but you should update to the latest version of the jailbreak and hotfix first. Some extensions might require reinstalling. Of course, if you have an old device, it's probably jail breakable even on the newest supported version. Latest jailbreak is for 5.6.5, and it's been confirmed that you can update to the latest version after jailbreaking and keep it.