France’s tax authority has revealed a data breach affecting over 678,000 individuals and businesses, after unauthorized access was gained to internal systems. The breach involved credentials from the Directorate General of Public Finances (DGFiP) and a third party, with the disclosure occurring on August 14, 2026.
Details of the Security Breach
The breach was traced back to June and July 2026, when unauthorized access was initially obtained. A malicious actor claimed responsibility for the breach on August 12 and 13, leading to an intensive forensic investigation by DGFiP.
Upon detecting unauthorized logins, DGFiP swiftly disabled the compromised accounts. However, the complexity of the attack initially obscured the data theft. Subsequent investigations revealed that the attackers had accessed and extracted sensitive tax-related information before access was cut off.
Scope of Compromised Data
The breach exposed personal tax data, including reference tax income, family quotient details, and withholding tax rates. Business information, such as company names and SIREN identifiers, was also accessed. Additionally, cadastral data like property addresses and size were compromised.
Despite the breach, taxpayer accounts on the online “Finances publiques” platform remained secure, with no exposure of usernames or passwords. The stolen data still poses a risk for phishing, identity fraud, and other scams targeting affected individuals and businesses.
Response and Future Measures
Following the breach confirmation, DGFiP notified France’s data protection authority, CNIL, and implemented stronger security protocols, including preventive disconnections from sensitive systems. Collaboration with the Ministry of Economy and Finance, the High Official for Defense and Security, and ANSSI is ongoing.
Investigators are working to determine the full extent of the breach, and DGFiP plans to notify all affected parties directly. Notifications will include details on accessed data and precautionary measures. A criminal complaint will be filed, and further updates will be released as investigations proceed.
To mitigate risks, affected users are advised to be cautious of unexpected tax-related communications, avoid clicking on unsolicited links, and verify requests through official channels.
