Standing in the school hallway.
Mold can be washed away easily but CDs made until the late 1980s do rot, even if they came from such hi-tech countries as West Germany or USA.
Japan-pressed CDs never rot. I'm absolutely impressed.
I've had to replace CDs because they got scratched up, broken, or bent but I don't think I've ever had to replace a CD for disk rot and I have hundreds of CDs (granted, some of which I haven't listened to in decades).
I acknowledge that that's only my own experience and I know glue rot has affected some of the billions of CDs ever produced but I'm skeptical that glue rot is as prevalent for CDs as it was for Laserdiscs.
I'm a CD die-hard. I buy vinyl very occasionally but I still prefer how music sounds on CD over how it sounds on either vinyl or mp3 and I also like how you can play a CD on nearly anything with an optical drive, which is also a thing I still like to have on my computers.