Pros
You get to work with extremely passionate individuals who believe in the product. The product itself is ambitious, challenging, and has a lot of potential! Everyone is willing to offer help, discuss, and be flexible.
It's still an early start-up, so if you're looking to work on solutions and designs with a lot of variables and data in a fast-paced environment, this is definitely the place.
Cons
You have to put in a lot of extra effort if you don't have a cybersecurity background. This could be a pro or con depending on your own perspective.
There is also not a lot of guidance (it IS a start up). You have to figure out what to do, what questions to ask, and work odd hours. All the difficulties that you would face working at a start up. Again, this could be a pro or a con depending on your personal perspective.