Originally Posted by prnoct90
I just got a Kindle Paperwhite that was unfortunately already at 5.3 when it arrived. Is there no solution for the time being?
No, not for the time being. (Except for taking it apart and accessing it via serial port).
I'm still actively searching for a new exploit, and I hope that a few others here do as well. I found a few minor glitches which allow to delete some files, or to create empty files (but unfortunately, part of the filename is fixed, which renders it useless). IOW: none of that allows for a full-fledged jailbreak (yet?).