Check manufactures date code
I've seen tires in showrooms that were 3-4 years old before they were sold. How long you have had them means nothing
Quote for truth, as they say.
It's both depressing and shocking just how little life you get out of tires before the owner is expected to replace them. 80,000 mile tread life means squat for those of us that drive only 10,000 miles per year if we are expected to only get around 4 years of life out of a tire before it's considered "too old".
Not sure how true (but not doubting it either), but I was told after 4 years of age, it is illegal (State, Federal?) for a shop to remount a tire. I can't even get my tires patched/plugged because they are just a wee bit over 4 years old, despite being in very good condition - as far as one can tell visually.
This just looks like cracking due to rubber degradation. How's the tread? I'd be inclined to drive on them until I could get replacements, full well being prepared for a sidewall blowout just in case. If the tread was down to 3 or 4/32", then I'd just get right on getting new ones.