Apparel retailer Stein Mart and software developer Social Annex Inc. didn’t do enough to secure their customers’ information, according to a new proposed class action.

Social Annex, also known as Annex Cloud, provides a service to internet merchants that lets customers use their username or password from other websites, like Facebook or Amazon, to log into the merchant’s site. In September, Stein Mart announced that code in Annex’s system allowed unauthorized users to capture customers’ information, including their names, email addresses, and payment card information, during several periods in 2017 and 2018.

Stein Mart and Annex didn’t take reasonable security...