Cyberattack Hits French Supermarkets: 50°C Fridges

A cyberattack on French supermarkets caused refrigeration systems to overheat to 50°C, forcing hundreds of stores to destroy millions of euros in fresh and frozen food. The French supermarket cyberattack, discovered on 12 October 2026, exploited outdated Danfoss cooling software and hit chains including Intermarché, E.Leclerc, Netto and Coopérative U.

What happened in the French supermarket cyberattack?

The attack began overnight on Sunday and was only noticed when staff opened stores on Monday morning. Hackers remotely manipulated the defrost function of internet-connected refrigeration controllers, causing units to run continuously and push temperatures to 50°C. Some fully-stocked fridges were heated for more than six hours, according to French media. The Paris prosecutor's office has opened a cyber-crime investigation, and France's ANSSI cybersecurity agency is coordinating with European counterparts. The incident highlights growing vulnerabilities in food supply chain cybersecurity.

How did hackers exploit Danfoss refrigeration software?

Affected stores used older Danfoss cooling units that could not be updated remotely. The vulnerable systems include Danfoss AK-SM 800A controllers, flaws in which were previously disclosed by security firm Claroty. A patch for three Danfoss controllers has been available since 18 September, but many older units remained on outdated firmware. Danfoss said affected units ran outdated firmware that could not be updated, leaving them exposed. This mirrors wider industrial control system vulnerabilities affecting critical infrastructure.

Which French supermarket chains were affected?

Around 400 of France's roughly 15,000 supermarkets were disrupted. Reports indicate Intermarché and Netto saw about 300 stores affected, Coopérative U confirmed disruptions at under 100 outlets, and E.Leclerc, Carrefour Market and Monoprix were also reportedly targeted.

Financial losses from spoiled food

Two Alsace supermarkets reported combined losses of €270,000, with one store owner citing €220,000 in damage. Nationwide, the cost is likely to run into the many millions. Coopérative U's CEO called the attack 'extremely serious and unprecedented.' The EU Food Commissioner condemned the incident as the 'weaponisation of food.' The attack raises urgent questions about European retail supply chain security.

Is the Albert Heijn cyber incident related?

Separately, Dutch retailer Ahold Delhaize reported a cyber security incident affecting Albert Heijn, Etos and Gall & Gall stores. That attack did not involve refrigeration, but disrupted electronic shelf labels and prevented online grocery deliveries. A spokesperson told Reuters there is no reason to see a connection between the two incidents. Still, the simultaneous events underscore rising cross-border retail cyber threats.

How can supermarkets protect refrigeration systems from cyberattacks?

• Apply firmware updates and patches promptly.
• Segment operational technology networks from IT systems.
• Monitor cooling controllers for unusual temperature commands.
• Develop incident response plans for food spoilage and fire risks.

FAQ

What caused French supermarket fridges to heat to 50°C?

Hackers exploited outdated Danfoss refrigeration software to trigger continuous defrosting, overheating units.

Which chains were hit by the cyberattack?

Intermarché, Netto, Coopérative U, E.Leclerc, Carrefour Market and Monoprix were affected, with about 400 stores disrupted.

How much damage did the attack cause?

Individual stores lost hundreds of thousands of euros; nationwide losses are estimated in the millions.

Is the Albert Heijn incident connected?

No confirmed link exists, according to Ahold Delhaize.