Substack, the hugely popular online content platform with 50 million active subscribers, has confirmed it has been hacked. Here’s what you need to know.

Substack said that customer data was accessed in October 2025, but wasn't discovered until early February.

Forbes contributors publish independent expert analyses and insights. Karin Eldor covers entrepreneurs and leaders in fashion & lifestyle. The momentum hasn’t slowed. Every time I went to hit publish ...

The hacker claims to have stolen nearly 700,000 Substack user records, including email addresses and phone numbers.

Substack won't share official numbers, but it seems like a pretty significant data breach.

"We're moving quickly," Farrah Storr, head of international at Substack, tells THR after hiring Mark Swierszcz as its new ...

Substack states that the security flaw has now been fixed and that a full investigation is underway. There are currently no ...

Lynch Carpenter is a national class action law firm with offices in Pennsylvania, California, and Illinois. Our firm has represented millions of clients in data privacy matters for more than a decade ...

Publishing platform Substack has disclosed a data breach that leaked nearly 700,000 user records after an unauthorized third-party exploited a security flaw.