(CNN) - Barnes and Noble said it suffered a massive cybersecurity attack that exposed customer information, including email addresses and other personal details.
The company sent an email Monday notifying customers of the data breach.
The bookstore chain said customers' financial information was not exposed, but transaction histories may have been.
Transaction history refers to purchase information related to books and other products bought from the company.
On Wednesday, the company’s Nook e-book platform suffered a temporary outage.