Not sure which toilet you have?
I don’t know of any water supply at the BASE of the toilet.
However, under constant pressure from City Water hookup — there could be a tiny hole or crack in your toilet valve at the back upper part of the toilet — or the supply water flushing line.
Water will migrate and be sometimes hard to determine where it is leaking from.
You need a flashlight and a magnifying glass, sometimes.
Our toilet valve started leaking because when I winterized it last Fall — I forgot about evacuating the toilet valve and water line.
Amazon to the rescue — bought (2) — one for backup on the road.
Easy to changeout if you remove the toilet from the floor. The new valve also comes with a new rubber ring that goes on the bottom of the toilet.
Could be something else entirely with your unit — but this is a common culprit — and what I found.
Also, when you remove the toilet — consider installing an inexpensive in-line valve for the water supply line at the back of the toilet. It will save a lot of headaches and hassle going forward.
Best Always,
Fred