https://www.itmedia.co.jp/news/article/2607/23/1260723053/ (Page 1/2)

A program change at Visa’s subsidiary Cybersource triggered a major credit card payment outage on July 16.

Some merchants could not process card payments, and transactions routed through networks like VisaNet and Mastercard were affected.

Cybersource acts as a gateway between payment processors and card networks, handling preprocessing, fraud screening, and tokenization.

The incident showed how heavily payment flows depend on a small number of gateway infrastructure layers.