If you're an NVIDIA user still on 32bit, you might want to think about finally updating as this month NVIDIA will be moving to only providing critical security updates for 32bit systems.
Not exactly surprising, as everything is gradually going 64bit. Our own user survey suggests a minuscule amount of people still on 32bit, with only 3 out of 2493 people telling us they're still lingering on 32bit.
In regards to security updates for their drivers, you have until January 2019.
See the official note from NVIDIA here.
On top of that, NVIDIA is also dropping their support for the Fermi series (GeForce 400/500) this month, with security updates also going on until January 2019. More on that here. This means, eventually, those on Fermi cards will be depending on the Nouveau open source drivers.