The newest WiiU system stability firmware update v5.5.1 patched 2 and maybe even more exploits!
MP4 exploit released by Mathew_Wi
It is incredibly bad, and likely won’t run any code for you whatsoever.
Yellow8s’ wiiu_browserhax_fright
https://twitter.com/smealum/status/686980799841701888
Note: Both exploits are labeled to be working for 5.4.0 and 5.5.0 only and will most likely not be of any use anymore! Additionally and in foresight to Hykems still planned-to-be-released IOSU exploit they are no reason to stay on a 5.4.0/5.50 firmware. We however still do NOT recommend updateing at all!
We will keep you posted..