Can LM339 comparator inputs go way above Vcc?
"Absolute maximum ratings" are about not destroying the device. "Electrical characteristics" or "Recommended operating conditions" are about proper functionality. For example, a supply voltage of zero volts is perfectly safe (well within maximum ratings!) but of course the device won't operate...

So, your voltage seems allowed by max. ratings, but will the comparator compare?

"Electrical Characteristics" in the datasheet:



There is fine print:



What's important is "will provide a proper output". Some comparators/opamps will misbehave or reverse the output if input voltage is outside correct operating conditions (but still inside maximum ratings), for example. In this case it will work. Datasheet page 13 confirms:



Most likely the internal transistors (highlighted in yellow) have been designed to have quite high Vebo rating, so the b-e junction doesn't break down under such high inverse voltage. Usually discrete BJTs have Vebo around 6V so the b-e junction would break down and avalanche around 6V when reverse biased.

Also there are probably ESD protection diodes from inputs to GND, but not from inputs to positive supply.