I had disabled our custom emojis due to the recent exploit but now that we've upgraded to 0.18.2, these should all be fixed. So I've reuploaded them.
Also reminder that if you've bought us a grog on Ko-fi, you can request to add a custom emoji for yourself added, as a little bonus. 
I think someone discovered you can easily build a 1x1 image to run code acting as a tracker using those emojis, it can log ip adresses and stuff. Are we sure we want that? Sorry I can't find the post again rn.
Sorry, do you have a link yo that? Because I don't see how that's possible
Yes found it, with bonus hostile guy calling devs tankies
https://raddle.me/f/fediverse/166674/lemmy-is-so-much-like-email-it-even-brought-back-spy-tracker
Ah that's not an exploit really,nor something that removing custom emojis would stop. It's not a massive issue anyway and I'm sure these kind of stuff will be sorted out soon as development has accelerated a lot lately