Ah, ok! That makes more sense.

So, central square is by no means dangerous, but the area does have a few homeless people who tend to congregate around the bus stop near the train station. For the most part, they will leave you alone as long as you mind your own business. They may approach you to ask for money. I think you will be fine commuting from that area but just something to keep in mind.

In general Cambridge is exceptionally safe.