Eurofiber France Reports Data Breach After Hackers Exploit Software Vulnerability

Eurofiber France has confirmed a data breach that occurred on November 13, 2025, after hackers exploited a software vulnerability to access its ticket management platform and customer portal. The incident resulted in the unauthorized exfiltration of customer data from the French division of the digital infrastructure company.

The security breach affected Eurofiber France and its regional brands, including Eurafibre, FullSave, Netiwan, and Avelia. The ATE customer portal, which serves the company’s cloud division, Eurofiber Cloud Infra France, was also targeted. The company stated the incident was contained and did not impact other Eurofiber entities in Belgium, Germany, or the Netherlands.

In a statement, Eurofiber reported that its security teams detected the intrusion quickly and activated incident response protocols. Within hours, the exploited vulnerability was patched, and the affected platforms were secured with enhanced protections. The company emphasized that sensitive information, such as banking details, was not compromised as it was stored on separate, unaffected systems.

Throughout the security incident, customer services remained operational without interruption. Eurofiber France has reported the breach to the relevant French authorities, including the CNIL, the nation’s data protection agency, and ANSSI, the national cybersecurity agency.

The company has also filed a formal complaint for extortion, suggesting the attackers may have made financial demands. While the specific nature of the software vulnerability was not disclosed, Eurofiber has implemented stronger authentication mechanisms, improved logging, and additional network segmentation to prevent future incidents.