Whether this constitutes cheating depends on the rules of a given college.
For instance, showing someone an old exam to someone who is currently taking the course can be considered an academic honor violation at my college as demonstrated when one student was punished by the honor board at my LAC for doing precisely that. Worse, it didn’t matter that the board conceded she did it unwittingly.
While her punishment consisted of writing an essay, she was also placed on judicial probation for the rest of her time there. This meant another honors violation would mean a suspension at the very least.
While I personally felt this case was unreasonably extreme, it does illustrate what may not be a big deal by some colleges/individuals might actually be to others.