So I am heading to Rio next week, but not paying attention to anything, I haven't realized my EU passport is expiring in 5 months. I think I might be denied entry since it isn't valid for the required 6 months and my US passport has no visa.

I was wondering, as this trip was a mix of a MR and vacation, can I just book a GIG-EZE ticket and transit in GIG? I know americans need a visa for this, but I still have a valid EU passport, and technically I won't be entering Brazil.