French Tax Data Leak Exposes 678k Accounts to Fraud Risk

A massive data breach in France has exposed the personal and financial records of over 678,000 individuals and professional accounts. The attack occurred in June and July 2026, with attackers gaining access to tax systems through a DGFiP employee and an approved third party.

The stolen records include reference taxable income, family quotient figures, withholding rates, company names, and SIREN identifiers, as well as cadastral information covering property addresses and surface areas. This data can be used for phishing and impersonation attempts, particularly against Bitcoin holders, although officials have found no exposed wallet keys or balances.

The breach was first publicized by a person using the alias ZeroBytes on a cybercrime forum on August 12, who offered the database without publishing a price. The French Finance Ministry has confirmed that taxpayer and business portals stayed secure, with attackers not compromising taxpayers' usernames or passwords.

Authorities are still assessing the exact records removed, but have notified the CNIL and involved ANSSI in the investigation. DGFiP plans to contact affected people and businesses directly by email or post next week.