The woman had been at the boarding gate when she decided to leave the airport's domestic terminal for one last cigarette, according to Fairfax.
On her return, she did not think she needed to be rescreened a second time.
But the mistake cost other passengers waiting to board a lengthy two-hour wait as they all had to be rescreened.
An Aviation Security (Avsec) spokesman told Fairfax it took about two hours to get back to normal and that all passengers needed to be rescreened to ensure the terminal was secure.
"The breach was quickly alerted to Avsec and all airport agencies worked seamlessly to identify and locate the passenger," the spokesman told Fairfax.
Avsec is now investigating how the woman managed to bypass security.
The security breach only added to the delays passengers were already facing due to fog around the airport.