Data breach reportedly targets India’s Kudankulam nuclear power plant

A significant data breach has exposed files connected to India's largest nuclear facility, Kudankulam Nuclear Power Plant in Tamil Nadu. The World Leaks ransomware group published the materials on the dark web, claiming the data originated from Reliance Group, a major contractor at the site. The exposed cache comprises nearly 19,000 files totalling 14.3 gigabytes, including purported blueprints, supplier details, meeting records, inspection documentation, and insurance policies spanning from 2016 to mid-2025.

Reliance Group confirmed a partial data breach affecting its server hosted by third-party provider Yotta and stated the government has been notified. The company's subsidiary, Reliance Infrastructure, holds a contract to design and construct infrastructure for the plant's Units 3 and 4, which remain under construction and are scheduled for operational status next year with combined capacity of 2,000 megawatts.

While the Nuclear Power Corporation of India asserted that publicly available information does not contain sensitive nuclear security details, cybersecurity analysts expressed concern. Nickolas Roth from the Nuclear Threat Initiative characterized the breach as posing serious safety risks and highlighted how such incidents reflect broader vulnerabilities in India's corporate cybersecurity preparedness. India's Computer Emergency Response Team is investigating the incident alongside the Nuclear Power Corporation's ongoing communication with Reliance.