hi there , i have scanned whonix website fastly with vega tool which included in kali linux for just a quick test. the results showed many of them into the high vulnerability and some in the medium. c this:-
1- http://i.imgur.com/ktnHuwo.jpg
2- http://i.imgur.com/ohMqOxR.jpg
3- http://i.imgur.com/MinfUPy.jpg
4- http://i.imgur.com/h0IPbJ7.png
5- http://i.imgur.com/tMww0EU.jpg
and this is nikto general search result:-

this is just a sample for the results and i didnt complete the search to the end , so if u r interesting in the results i can show it all plus i can use another tools if u want.