I started a new campaign with friends and I was warned that there would be a bit of homebrew. So far the dm has a nice narrative and its fun, but the only problem is we are level 5 and players casuallt have 23-25 as some of their stats. One was litteraly shocked that I only had an eighteen as my highest. Not sure this is a problem, but feels a little weird when one of our spellcasters has a strength score that is around like 7 or 8 above mine as the parties paladin. Just wanted to rant about this.

Damn.

My rant would have been much longer, and featured a lot more bad words.

I'd be finding a new group before I said something I'd regret

I got too fed up just thinking about the session to finish it.

sometimes the only thing you can do is walk away

It might get better. I talked to the dm and he was having similar thoughts and just wasnt sure how to adress it. Now they are going to try and talk to them.

How is it that they have stats like that? Maybe ask if you can use the same system they are using?

As Wysperra says I think the first question needs to be how they got stats like that at level five. Assuming they took an ASI at level 4 ton get a 25 in something they'd need to have started with a 23 and that's just not possible with any of the three standard methods. Even if they needed magic items to get there that's an awful lot of pretty high level items at too low a level if they've all got stats like it

Actually, my question is why the DM didn't work with you to ensure you had a comparable character. It might just be as simple as the DM paying too little attention to PC creation and those other players just were pulling a fast one

Maybe time for a session zero and rolling up new characters

Did the DM work with these other players and not you? Did the other players just show up with these characters without the DM looking at them? Are these players new? Maybe they thought the 27 point buy was just 1 for 1 and not scaling?  More information is needed, but agree characters need a redo or just start from scratch with session zero. 

Maybe they rolled 4d6 and didn't know they are only ment to pick the 3 highest numbers. And not add all 4 rolls together

I feel like this lacks context. How did they get such high scores? RAW, they're impossible and while you often get the "there's always one..." person that gets things wrong, if they're all doing it, it sounds like there was a homebrew rule that lets them do it. If everyone can do it...then it's often fine. Enemies need to be boosted because if you have Str 24, you're doing an average of 12.5 damage rather than 9.5 (which is a midgame output rather than a starter character output).

So really, the question is why you're really low in comparison. Was it down to chance? Did you not take advantage of new rules? Did they not tell you about the modified rules? Or are they just cheating and hoping the DM won't stand up to them? If it's because of the former two reasons, then I'm afraid to say that it's on you and there's nothing to get angry about (although if it's down ti chance, I can see why it would bother you). If it's one of the latter two reasons, then I'd consider bailing. That's pretty toxic, and they'll likely be trying shenanigans throughout the game.