JFK Airport suffered yet another security breach yesterday after a traveler was able to access a passengers-only area a day before his scheduled flight, sources said.

Wilfred Isidore, 42, of Spring Valley in Rockland County, missed his Haiti-bound flight yesterday afternoon and then switched his ticket to the next morning.

But Isidore then immediately headed for his gate and breezed past a TSA agent who let him through without noticing the discrepancy, according to the sources.

Isidore, who has a prior arrest for allegedly assaulting a cop in New Jersey, then allegedly set off an alarm after opening a door to get to an outside off-limits area, where he smoked a cigarette.

A startled American Airlines clerk alerted security to the odd behavior and Isidore allegedly took off running before being subdued.

He was charged with criminal trespass, authorities said.