The 12 Volts looks very bad if it's only 8 Volts, either it's something wrong with your PSU or something is loading terribly on your PSU, if you have anothe PSU at hand try to switch over and check if you get the same readings, otherwise there's some HW problems on your mobo, can be everything from the local voltage regulators to some piece of HW, if this is a desktop PC you could check out the mobo if some of the capacitors have popped...
EDIT:
Looking around and fount this post..
http://www.tomshardware.co.uk/answers/id-1980767/extremely-high-temps-cputin-auxtin-hwmonitor.html
it says the CPUTIN and AUXTIN could be missreading due to faulty sensors.
Perhaps it would be best first try get hands on a multimeter and measure the 12V voltage and check the spare powersupply cables, between Black-Yellow=12Volt, between Black-Red=5Volt, also if you touch with your fingers and can't find any extremely hot heatsink it may be no problem at all..