sudo apt-get-upgrade
sudo apt-get dist-upgrade
sudo apt-get update
sudo apt-get install libnss3

(Which says I have the newest version)

Here is what I get when I runsudo apt-cache policy libnss3

libnss3:
  Installed: 2:3.19.2.1-0ubuntu0.15.04.2
  Candidate: 2:3.19.2.1-0ubuntu0.15.04.2
  Version table:
 *** 2:3.19.2.1-0ubuntu0.15.04.2 0

https://askubuntu.com/questions/954918/cant-lauch-google-chorme-stable-getting-out-of-date-nss-libnss3