If it is superficial then just wash them - water and soap - as suggested above.
If the metal film is rotten in places (underneath the plastic sandwich) then there is nothing that can be done - copy the CD before it gets any worse (youu lose more tracks).
"CD rot" is something you can google it is rare but I have around 10 CD's that suffer (out of a thousand or more)
If the metal film is rotten in places (underneath the plastic sandwich) then there is nothing that can be done - copy the CD before it gets any worse (youu lose more tracks).
"CD rot" is something you can google it is rare but I have around 10 CD's that suffer (out of a thousand or more)