Noticing that brake fluid seems to be coming up out through the caps on the top of the master cylinder.

Is this possibly just the seals/gaskets on the caps are bad? Or something else causing it?

I did open them up yesterday, prior to realizing they were leaking, and fluid didn't seem to be overfilled. It says to have fluid up to the "rings". Though wasn't certain where the ring mark was or what it meant by rings. Only today, when I was back under the hood, did I notice it.

I have a paper copy of the owners manual and the Haynes online repair manual. Neither really accurately explains

 

There should be a gasket between the cap and the master cylinder. It is supposed to seal it so no fluid gets out. Yours may be bad or the cap is not sealing on it. It looks something like this...

 

Thanks, that points me in the right direction. Though my MC has two individual caps, so will verify they have gaskets and just replace them regardless.