Account information for members of the Dunkin' Donuts "DD Perks" program was used to access other online profiles.

A data security breach at one of Dunkin's vendors allowed a third party access to username and password information for some DD Perks accounts, according to a letter sent to affected members obtained by 6 ABC Action News.

The third party then apparently tried using the information to break in to other online accounts across the internet. The vendor, whose name was not disclosed, was able to stop most of the attempted uses, but not all.

The Perks accounts were especially at risk if the same username and password was used for other accounts.

Those whose accounts were accessed were sent a message forcing them to reset their password. Dunkin' also assigned new numbers to the cards registered with the DD Perks program.

The DD Perks program allows customers to register gift cards on an app and earn points toward free food and beverage. According to QSRmagazine.com, the program has nearly 9 million members.

Sign up for the WPG Talk Radio 104.1 Newsletter

Get South Jersey news and information e-mailed to you every week.