--- title: Substack confirms data breach affects users’ email... description: Substack disclosed a data breach where an unauthorized party accessed user email addresses, phone numbers, and internal metadata in October 2025, though the... canonical: https://daily.dev/posts/substack-confirms-data-breach-affects-users-email-addresses-and-phone-numbers-0gw9ypvod twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Substack confirms data breach affects users’ email addresses and phone numbers | daily.dev og:description: Substack disclosed a data breach where an unauthorized party accessed user email addresses, phone numbers, and internal metadata in October 2025, though the... og:url: https://daily.dev/posts/substack-confirms-data-breach-affects-users-email-addresses-and-phone-numbers-0gw9ypvod og:image: https://api.daily.dev/og/posts/0Gw9YPVOd.png og:image:alt: Substack confirms data breach affects users’ email addresses and phone numbers og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Substack confirms data breach affects users’ email addresses and phone numbers **[TechCrunch](https://daily.dev/sources/tc)** · 2 min read · 0 upvotes · 0 comments ## Summary Substack disclosed a data breach where an unauthorized party accessed user email addresses, phone numbers, and internal metadata in October 2025, though the breach wasn't discovered until February 2026. Sensitive data like passwords and financial information remained secure. The company has fixed the vulnerability and launched an investigation, but hasn't revealed the breach's scope, how many of its 50+ million active subscriptions were affected, or why detection took five months. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [DoorDash confirms data breach impacting users’ phone numbers and physical addresses](https://daily.dev/posts/doordash-confirms-data-breach-impacting-users-phone-numbers-and-physical-addresses-uqflwqnoi) · TechCrunch · 0 upvotes · 0 comments - [Have I Been Pwned: SoundCloud Data Breach](https://daily.dev/posts/have-i-been-pwned-soundcloud-data-breach-sddcswlvy) · Hacker News · 0 upvotes · 0 comments - [Starbucks Discloses Data Breach Affecting Hundreds of Employees](https://daily.dev/posts/starbucks-discloses-data-breach-affecting-hundreds-of-employees-pliaagwou) · IT Security Guru · 0 upvotes · 0 comments --- Tags: [#tech-news](https://daily.dev/tags/tech-news), [#cyber](https://daily.dev/tags/cyber), [#privacy](https://daily.dev/tags/privacy), [#data-breach](https://daily.dev/tags/data-breach) [View this post on daily.dev](https://daily.dev/posts/substack-confirms-data-breach-affects-users-email-addresses-and-phone-numbers-0gw9ypvod) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Substack confirms data breach affects users’ email addresses and phone numbers","url":"https://daily.dev/posts/substack-confirms-data-breach-affects-users-email-addresses-and-phone-numbers-0gw9ypvod","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/substack-confirms-data-breach-affects-users-email-addresses-and-phone-numbers-0gw9ypvod"},"datePublished":"2026-02-05T14:57:15.918Z","dateModified":"2026-02-26T21:11:46.334Z","description":"Substack disclosed a data breach where an unauthorized party accessed user email addresses, phone numbers, and internal metadata in October 2025, though the...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/e9f4b1f51249719d45b0e0960c21eeb9?_a=AQAEulh","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/e9f4b1f51249719d45b0e0960c21eeb9?_a=AQAEulh","isAccessibleForFree":true,"articleSection":"TechCrunch","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"TechCrunch","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/tc","url":"https://daily.dev/sources/tc"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/substack-confirms-data-breach-affects-users-email-addresses-and-phone-numbers-0gw9ypvod","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"tech-news,cyber,privacy,data-breach","timeRequired":"PT2M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"TechCrunch","item":"https://daily.dev/sources/tc"},{"@type":"ListItem","position":3,"name":"Substack confirms data breach affects users’ email addresses and phone numbers"}]} ```