@avl Unfortunately I had to migrate back to Chrome. I was too bored with Opera's not playing simple mp3 file (https://goo.gl/Nt1qSg) animated GIF's in Twitter... Instead of improving the browser Opera's team is making regres.
You can find which version comes from where with "apt-cache policy libnss3".
However, both are too old now, because all the working repos of ubuntu (14.04, 16.04 and to 17.10) have 3.28 (2:3.28-whatever), so yes, an update is mandatory for you now.