I live in New york State Apparently i've been being taxed in PA and NY since july after getting a raise I've asked my job to fix this, but how much trouble am i in?

I got a raise in July and apparently about a month later i started getting taxed in the state of PA as well, i never noticed this until the w2 form i saw today. how much trouble would i be in? could they go back and correct the taxes from that long ago? Would it just be that i owe some taxes in new state? its a few thousand dollars that it says i've made wages on in PA

Thank you!