--- title: Substack says intruder lifted emails, phone numbers description: Substack disclosed a security breach where an unauthorized intruder accessed user contact details including email addresses, phone numbers, and account... canonical: https://daily.dev/posts/substack-says-intruder-lifted-emails-phone-numbers-m6fm4amgt twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Substack says intruder lifted emails, phone numbers | daily.dev og:description: Substack disclosed a security breach where an unauthorized intruder accessed user contact details including email addresses, phone numbers, and account... og:url: https://daily.dev/posts/substack-says-intruder-lifted-emails-phone-numbers-m6fm4amgt og:image: https://api.daily.dev/og/posts/m6Fm4aMgT.png og:image:alt: Substack says intruder lifted emails, 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 says intruder lifted emails, phone numbers **[The Register](https://daily.dev/sources/theregister)** · 3 min read · 0 upvotes · 0 comments ## Summary Substack disclosed a security breach where an unauthorized intruder accessed user contact details including email addresses, phone numbers, and account metadata during October 2025. The incident went undetected for months until February 2026. While passwords and financial data were not compromised, a threat actor has posted nearly 700,000 alleged user records on cybercrime forums. The company has patched the vulnerability and launched an investigation, warning users to watch for phishing attempts. ## 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 - [BreachForums Breach Exposes Names of 324K Cybercriminals, Upends the Threat Intel Game](https://daily.dev/posts/breachforums-breach-exposes-names-of-324k-cybercriminals-upends-the-threat-intel-game-gniyjeusk) · Security Boulevard · 0 upvotes · 0 comments --- Tags: [#tech-news](https://daily.dev/tags/tech-news), [#security](https://daily.dev/tags/security), [#cyber](https://daily.dev/tags/cyber), [#data-breach](https://daily.dev/tags/data-breach) [View this post on daily.dev](https://daily.dev/posts/substack-says-intruder-lifted-emails-phone-numbers-m6fm4amgt) ```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 says intruder lifted emails, phone numbers","url":"https://daily.dev/posts/substack-says-intruder-lifted-emails-phone-numbers-m6fm4amgt","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/substack-says-intruder-lifted-emails-phone-numbers-m6fm4amgt"},"datePublished":"2026-02-05T19:57:57.974Z","dateModified":"2026-02-26T21:10:19.119Z","description":"Substack disclosed a security breach where an unauthorized intruder accessed user contact details including email addresses, phone numbers, and account...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/b4b72df7cfa8f7f5b05c67ff9644477f?_a=AQAEulh","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/b4b72df7cfa8f7f5b05c67ff9644477f?_a=AQAEulh","isAccessibleForFree":true,"articleSection":"The Register","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":"The Register","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/66aa2113fdad463992ffcbf0e8963fda","url":"https://daily.dev/sources/theregister"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/substack-says-intruder-lifted-emails-phone-numbers-m6fm4amgt","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"tech-news,security,cyber,data-breach","timeRequired":"PT3M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"The Register","item":"https://daily.dev/sources/theregister"},{"@type":"ListItem","position":3,"name":"Substack says intruder lifted emails, phone numbers"}]} ```