Yes, definitely that.Attack the problem now, while the rust is minimal,
And is your cat damaged? I had similar on my coupé and I pointed out to the test man. He hadn't noticed it. So he marked it as split but not critical. No problem as I had another in stock but he did annoy me rather. The last test guy kept saying "... belle voiture .." from underneath so I'll use hime next time.
Sorry to diverge.