Has Substack had a data breach?
Substack appears in 1 tracked breach, affecting around 663,121 accounts in total.
Known incidents
- SubstackOctober 23, 2025663,121
Data exposed across these incidents
Email addressesPhone numbers
If you have an account with Substack, change your password and turn on two-factor authentication, and treat messages that reference the company with caution. Open any incident above for what was exposed and what to do.