CyberHappenings logo
☰
Home Browse Watchlists Experimental About

Track cybersecurity events as they unfold. Sourced timelines. Filter, sort, and browse. Fast, privacy‑respecting. No invasive ads, no tracking.

Substack Data Breach Exposes User Email Addresses and Phone Numbers

First reported
Last updated
1 unique sources, 1 articles

Summary

Hide ▲

Substack has notified users of a data breach that occurred in October 2025, during which attackers stole email addresses and phone numbers. The breach was discovered in February 2026. The platform assured users that no credentials or financial information were accessed. A threat actor later leaked a database containing 697,313 records on BreachForums, claiming the data was scraped. Substack has patched the vulnerability and warned users about potential phishing attempts. Substack has a history of privacy incidents, including a 2020 email exposure. The platform has grown significantly since its launch in 2017, reaching five million paid subscriptions by March 2025.

Timeline

  1. 05.02.2026 14:54 1 articles · 10h ago

    Substack Data Breach Discovered in February 2026

    Substack discovered a data breach in February 2026 that occurred in October 2025. Attackers stole email addresses and phone numbers but did not access credentials or financial information. A threat actor leaked a database on BreachForums containing 697,313 records of allegedly stolen data. Substack has patched the vulnerability and warned users about potential phishing attempts.

    Show sources
    Open in new tab

Information Snippets