https://www.cnbc.com/2017/09/14/equifax-says-web-server-vulnerability-led-to-hack.html

Credit reporting company Equifax blamed a web server vulnerability in its open-source software, called Apache Struts, for the recent data breach that compromised personal details of as many as 143 million U.S. consumers.

The massive data breach had exposed valuable information to hackers between mid-May and July and sent Equifax shares tumbling, the company said last week.