When Freezers Become Ovens: Why OT Needs Zero Trust Now
Zscaler, Tuesday, November 3rd, 2026
Zscaler uses attacks that turned supermarket freezers into ovens to argue that operational technology needs zero trust.
Zscaler describes attacks in which grocery chains across Europe, French supermarkets including Intermarché, Carrefour and E. Leclerc, and U.S. military commissaries had refrigeration units remotely forced into a continuous defrost cycle overnight, destroying perishable food.
Because defrost is a legitimate state, controllers suppressed alarms, and the Pentagon is treating the episodes as coordinated cyberattacks.
Zscaler attributes the attacks to CVE-2025-41450, an authentication bypass in Danfoss AK-SM 800A controllers found by Claroty's Team82, with thousands of controllers exposed to the internet and largely unpatched.
It argues that OT devices were not designed for today's threats and need zero trust protection.