Substack data breach exposed user email addresses and phone numbers for months before CEO Chris Best confirmed the October ...

Substack says hackers accessed user emails, phone numbers, and internal metadata in October 2025, with a database of 697,313 ...

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

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

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

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

Popular newsletter platform Substack is the latest company to confirm it experienced a security incident, in which users' email addresses and phone numbers were exposed. According to an email sent to ...

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.