Newsletter platform Substack has confirmed a data breach in an email to users. The company said that in October, an “unauthorized third party” accessed user data, including email addresses, phone ...

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 has confirmed that a security breach exposed limited user contact information, including email addresses and phone numbers, prompting renewed scrutiny of data protection practices across ...

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 ...

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 ...