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

Substack, the hugely popular online content platform with 50 million active subscribers, has confirmed it has been hacked.

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

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

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

The digital publishing platform Substack has told some of its users that their data was stolen in a security breach. The ...

Exclusive: Site takes a cut of subscriptions to content that promotes far-right ideology, white supremacy and antisemitism ...

If you have accounts on any of these services, now's a good time to check your security settings. Plus more from a busy week in cybersecurity chaos.

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

Substack confirms a major data breach exposing user emails and phone numbers. What’s behind the breach, and what’s next?

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 ...