Tickets on trips from Hong Kong to Portugal were sold on the airline's website for $1,512, instead of $16,000 usually charged for a similar journey.
The carrier said it would honour the tickets as it investigates the cause of the error.
It extends a recent run of blows to the firm including a huge data breach.
The mispriced fares were available on Cathay Pacific's website on Sunday.
First-class flights from Lisbon to Hong Kong - via London with a connecting flight - were offered for $1,512 (£1,177), according to the South China Morning Post.
A similar first-class journey through Frankfurt would cost $16,000.
In a statement, the Hong Kong carrier said it would honour the tickets.
"We are looking into the root cause of this incident both internally and externally with our vendors," it said.
"For the very small number of customers who have purchased these tickets, we look forward to welcoming you on board to enjoy our premium services."
Just two weeks ago the airline made the same blunder.
Lucky flyers made off with business-class seats on flights from Vietnam to New York for about $675 return. They should have cost $16,000.
At the time, the carrier acknowledged its "mistake" and again, said it would welcome the passengers onboard.
Airlines have a mixed history of honouring tickets sold in error.
Singapore Airlines, for example, honoured tickets sold for less than half price in 2014. But United Airlines cancelled transatlantic tickets sold for less than $100 by a "third party software provider" the following year.