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

Substack has confirmed a major data breach that exposed emails and phone numbers for approximately 700,000 users, with the ...

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

If you’re impacted by the security incident, you’ll hear directly from the brand with an email from Substack's CEO.

The digital publishing platform Substack has told some of its users that their data was stolen in a security breach. The affected account holders had their email addresses and phone numbers scraped in ...

The company has emailed affected users after a dark web source claims the data of almost 700,000 users was compromised.