Norton Security Products Contain Critical Vulnerabilities clarification

OK  in real practical terms what does this mean? I am just a home user. So does it mean I might be attacked via an email? If I go to  a dangerous website? or can it just attack my PC even if I am only open to the internet (not on a web page but just internet connected)?

what would it do to my PC?

If I got infected would NIS v21 detect an infection?