Quiberon: municipal services disrupted after a cyberattack

On 3 May 2026, the town of Quiberon — a coastal commune in the Morbihan department of Brittany, France — was hit by a ransomware attack that disrupted part of its municipal IT systems. The city disclosed the incident publicly on 5 May 2026, and the Qilin ransomware group claimed responsibility, listing the commune on its dark-web leak site on 6 May.

The attackers gained access to the municipality's network, exfiltrated data, and then encrypted systems to render them unusable before demanding a ransom. In line with the recommendations of the French authorities, the City refused to pay. Municipal teams, supported by cybersecurity specialists (Breizh Cyber and Formind), worked on a progressive and secured reconstruction of the IT infrastructure.

The town confirmed that personal data may have been accessed and exfiltrated. While the exact scope was not quantified publicly, residents were advised to stay alert for suspicious solicitations (phishing, scams) in the following months. Exposed-data categories indicated or implied:

• Personal data of residents and/or municipal staff held in town-hall systems

During the incident, several municipal services were temporarily unavailable or slowed; the city asked residents to defer non-urgent requests. A criminal complaint was filed with the Gendarmerie, whose anti-cybercrime office opened an investigation, and the CNIL and ANSSI were notified. Most services, including the issuance of identity documents, were subsequently restored as the rebuild continued.