People search Epsilon data breach timeline because the brand sits on billions of accounts, credentials, and cloud workloads. BreachHistory indexes 3 Epsilon-linked incidents, with headline counts up to 250M+ in catalog rows. This page maps every attested event through 2026 with internal links to canonical records.
Why Epsilon breach history matters
Epsilon operates in Technology. Across indexed rows, recurring themes include mixed intrusion and disclosure events. Understanding the chronological pattern helps security teams, customers, and regulators separate confirmed disclosures from forum marketing.
Full timeline through 2026
2014 — — Epsilon: Hackers obtained the names and email addresses of…
Cataloged incident. Hackers obtained the names and email addresses of customers of dozens of businesses maintained by Epsilon Management LLC. Epsilon said only 2% of its database had been invaded, but dozens of major companies across a variety of industries responded by emailing their customers to notify them of the breach. The companies include Citigroup Inc., Capital One Financial Corp., JPMorgan Chase & Co., 1-800-Flowers.com Inc., Best Buy Co. Inc., L.L. Bean Inc. and Target Corp. Experts state that the b Exposed categories include Personal information. No attested victim count is published for this row yet. See the epsilon2014 and canonical BreachHistory entry.
2011 — — Epsilon: Epsilon, an email service provider for companies,…
Cataloged incident. Epsilon, an email service provider for companies, reported a breach that affected approximately two percent of its 2,500 clients. Only e-mail addresses and names were stolen. Epsilon has not disclosed the names of the companies affected or the total number of names stolen. However, millions of customers have received notices from a growing list of affected companies (http://www.databreaches.net/?p=17374), making this the largest security breach ever.The Secret Service is investigating this breac Exposed categories include Personal information. BreachHistory cites approximately 250M+ affected records in this row. See the epsilon2011 and canonical BreachHistory entry.
2011 — — Epsilon: Names & email addresses of customers of Barclaycard…
Cataloged incident. Apr 2011. Names & email addresses of customers of Barclaycard US, Capital One, JP Morgan, Citigroup & other firms have been stolen. BreachHistory cites approximately 3M+ affected records in this row. See the epsilonu and canonical BreachHistory entry.
Patterns and analysis
- Mixed intrusion and disclosure events — appears across multiple Epsilon catalog entries; prioritize controls that address this class of failure.
- Record-count hygiene — BreachHistory indexes actor-cited figures separately from company-confirmed totals; read each row's technicalWriteup before treating counts as fact.
- 2026 monitoring — New disclosures roll into this timeline as they are verified or labeled unverified per catalog policy.
What to do if you may be affected
- Step 1: Enable phishing-resistant MFA on every account tied to this brand.
- Step 2: Use unique passwords and a password manager—breach rows often involve credential reuse.
- Step 3: Monitor official company breach notices and regulator filings, not dark-web downloads.
- Step 4: Review OAuth app permissions and revoke unused third-party integrations.
- Step 5: Bookmark the Epsilon company page for new 2026+ disclosures.
Canonical BreachHistory hub
Explore every indexed row: breachhistory.com/epsilon · Latest: epsilon2014.
Sources: BreachHistory catalog (3 rows for Epsilon), company and regulator disclosures cited in individual breach records.