Fallout 4- Max S.P.E.C.I.A.L Glitch!
To do this you will need to get out of vault 111 and accuire Dog Meat your first trusty companion. Then you will need to go inside your characters old house (it will be the one with Codsworth outside it). Then you will go to your baby's room and pick up the book under his old crib. You get to pick one SPECIAL stat to increase, but don't worry that is where this glitch comes into play. You pick up the book and drop it in a safe location. You will then tell Dog Meat to pick it up, and when he bends over to grab the book you will too. This will effectively duplicate the book and you get to pick another SPECIAL stat to increase. You can do this glitch as many times as you want and eventually you will max out every single stat.
This glitch was found by Reddit user B-FOXY all credit for the glitch goes to him.