Update: 12:04 p.m. EST: American Airlines has announced that a "few hundred" of the 200,000 flights in December currently do not have pilots assigned, CNBC reported.

Original story: A scheduling glitch could leave American Airlines passengers stranded for one of the busiest travel times of the year.

Multiple media outlets are reporting that American Airlines is blaming computer issues that allowed all pilots to take vacation over Christmas week.

The union was notified last week that there was an issue with the system through which pilots request and are granted time off, CNBC reported.

Because of the problem, there are thousands of flights in December that could be affected, The Chicago Tribune reported.

American Airlines released the following statement:

"We are working diligently to address the issue and expect to avoid cancellations this holiday season. We have reserve pilots to help cover flying in December, and we are paying pilots who pick up certain open trips 150 percent of their hourly rate – as much as we are allowed to pay them per the contract. We will work with the APA to take care of our pilots and ensure we get our customers to where they need to go over the holidays."

The Allied Pilots Association had filed a grievance, saying that the offer violates the labor contract between the union and company, The Tribune reported.

There are flights without either a captain, first officer or both, with itineraries from or to Dallas-Fort Worth, Boston, Miami, New York, Philadelphia, Salt Lake City and Charlotte, Bloomberg reported.