A question that causes bad consequences by the very act of asking it.
Originating from Israeli-Army slang. The original/canonical kitbag question explains its meaning quite well:
A military boot-camp squad commander orders the squad to take a break and meet at some place after 10 minutes.
A soldier asks: "Do we need to bring our kitbags?" (A kitbag is heavy bag that soldiers have)
Commander: "Yes, of course, bring your kitbags!"
The commander would had not given the order had the kitbag question not been asked.. Because of asking the question, the soldier has caused grief for himself and the fellow soldiers from his squad.