What Security Concerns should I Have

[Ca_lvn]

Hello so I'm using a unlocked S7 930U, I use my phone for multiple purposes, one line shopping, banking, Samsung Pay, general web browsing and many other functions, I enjoy a unlocked phone without all the extras, if I check updates it says all are current, I'm really not interested in upgrading to N just being safe security wise.
Thanks for your input.

 

[Tim1954]

Not sure what you're asking here. Software updates are not a security issue if they are legit (meaning you went to settings and checked for, and authorised the update).
Lots of ppl are unhappy with nougat, but then, lots aren't.. If you don't like change, perhaps stay with Marshmallow.
Security is more about what you do with the device... Sideloading apps, opening dodgy attachments, clicking on popups especially on dodgy websites...
Having other ppl handling your phone...

 

[AxlMyk]

Having other ppl handling your phone...

^^^THIS^^^