Powertrain / Under The Hood • Transmission case leak

My mechanic informed me that the transmission casing is leaking onto the exhaust. He told me to go to the dealer and it may be covered under warranty (<100k mi). I'm at 98,500 miles, but it's a 2012.

Is this a real issue that I should look to get fixed right away? Expensive repair? Dealer covered for a 12 year old model?

Thanks in advance for your insights.

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