Reported by 4 outlets

Timeline

1. original reporting

   French Tax Authority Data Breach Impacts 678,000 Individuals and Businesses

   cyberpress.org · 56d ago · August 18th, 2026

   France’s tax authority, the Direction générale des Finances publiques (DGFiP), has disclosed a data breach affecting approximately 678,000 individuals and businesses after attackers gained unauthorized access to its information systems using impersonated credentials. The French Ministry of Economy and Finance announced on August 14 that the intrusions occurred in June and July 2026. A malicious actor claimed responsibility for the access on August 12 and 13, prompting a deeper investigation into the incident’s scope and consequences. According to DGFiP, the attackers accessed internal systems by impersonating the credentials of both a DGFiP employee and an authorized third party. The authority said it immediately disabled all accounts associated with the identified incidents after detecting the intrusions. French Tax Authority Data Breach Initial access-control reviews did not identify evidence of data theft. However, subsequent investigations determined that the compromised accounts had been used to consult and extract data before they were terminated. DGFiP attributed the failure to initially detect exfiltration to the sophistication of the attack. The agency has not disclosed the technical method used to obtain or impersonate the credentials, whether multi-factor authentication was bypassed, or the identity of the threat actor behind the activity. The breach involved tax-related and cadastral information belonging to private individuals and professional entities. For indiv

2. update from bleepingcomputer.com

   French tax authority data breach affects 678,000 individuals

   bleepingcomputer.com · 57d ago · August 17th, 2026

   This incident was discovered after a threat actor using the "ZeroBytes" handle claimed the attack and listed a stolen database for sale on August 12 on the PwnForums hacking forum. "The in-depth investigations conducted since August 12, 2026, have established that, prior to their interruption, these access points had been used to consult and extract data concerning a total of 678,000 individuals and professionals, including tax data such as reference tax income, family quotient, and withholding tax rate, and, for businesses, data such as their company name and SIREN number," the French Finance Ministry said . "Cadastral data relating to addresses and property sizes were also accessed. As soon as these data breaches were identified, the French Public Finances Directorate (DGFIP) notified the French Data Protection Authority (CNIL). User IDs and passwords were not compromised." After detecting the attack, the French tax administration shut down access to sensitive information systems and continues investigating the incident with the help of the National Cybersecurity Agency of France (ANSSI) to assess the breach's full impact.

3. mentioned by securityweek.com

   680,000 Impacted by French Tax Authority Data Breach

   securityweek.com · 57d ago · August 17th, 2026

4. update from gbhackers.com

   French Tax Authority Cyberattack Exposes Tax Data of 678,000 Individuals and Businesses

   gbhackers.com · 56d ago · August 18th, 2026

   According to a press release from the French Ministry of Economy and Finance, issued on August 14, 2026, the intrusions occurred during June and […] The post French Tax Authority Cyberattack Exposes Tax Data of 678,000 Individuals and Businesses appeared first on GBHackers Security | #1 Globally Trusted Cyber Security News Platform .