A United Airlines flight attendant made a mistake that could have posed a huge security threat (UAL)

A United Airlines employee posted security codes online over the weekend that are used to access the cockpit, possibly compromising security, according to a report from The Wall Street Journal.

According to The Journal, the flight attendant who posted the information online did so by accident.

In a statement to Business Insider, United said it used multiple methods, including access codes, to ensure security.

"We have learned that some cockpit door access information may have been made public," the company said in a statement to Business Insider. "The safety of our customers and crew is our top priority and United utilizes a number of measures to keep our flight decks secure beyond door access information.

"In the interim, this protocol ensures our cockpits remain secure. We are working to resolve this issue as soon as possible."

The airline did not say specifically what other measures entailed. But according to the Journal report, the airline also requires pilots to visually verify a person's identity before granting access to the cockpit.

According to the report, the company sent out a memo to employees notifying them that this information had been made public and reminding them to take extra steps when granting access to the cockpit. No delays had resulted because of the incident, The Journal reported.

United has been in crisis mode recently.

The airline came under fire in April following the forcible removal of passenger David Dao, a 69-year-old doctor, from a flight from Chicago to Louisville, Kentucky.

On April 9, Dao was dragged off flight 3411 by Chicago Aviation police officers after refusing to give up his seat on the full plane for airline employees. Other passengers on the place recorded the incident in video footage that quickly went viral.

The footage sparked public outrage, not only against United but against the airline industry in general for its practice of overbooking seats and for its treatment of passengers.

As a result, United announced policy changes affecting both customers and employees. Some of the changes the company said it was implementing included more annual training for employees and an overall reduction in overbooking.