Newsletter platform Substack is notifying users of a data breach after attackers stole their email addresses and phone numbers in October 2025. Although the incident occurred four months ago, CEO ...

The company has emailed affected users after a dark web source claims the data of almost 700,000 users was compromised. Substack, a high-profile publishing platform widely used by academics, ...

Substack recently confirmed that it had suffered a data breach exposing user data like email addresses and phone numbers, though the company claims the incident did not include financial information ...

Substack confirms October 2025 breach exposing user emails, phone numbers, and metadata CEO Chris Best assured no financial data or credentials were accessed; hole patched and investigation ongoing ...