Skip to content
Substack Breach Exposes User Emails and Phone Numbers from October Hack

Substack Breach Exposes User Emails and Phone Numbers from October Hack

First seen 5 Feb 2026, 18:32 UTC

Article Content

Browse articles
ThreatCluster AI
ThreatCluster March 12, 2026 at 13:27 UTC

Substack has disclosed a security breach that exposed user email addresses and phone numbers due to a hack that occurred in October 2025. The breach went undetected for four months, with CEO Chris Best confirming that no passwords, credit card information, or financial data were compromised. Users were notified on February 3, 2026, but details about the number of affected users and the technical specifics of the vulnerability remain undisclosed.

Start a free Starter trial for enhanced analysis

Ask AI about this cluster

Updated 182d ago How this analysis works

More articles in this cluster (30)

Following this threat?

Track Substack in your own feed — you're alerted when they show up in new reporting, leak sites or exploitation.

Free account · no card needed