Sensitive documents from the Kudankulam Nuclear Power Plant, including facility details, have been leaked by a ransomware group. Reliance Group, a contractor, confirmed a partial breach on a third-party server, prompting an investigation by national cybersecurity authorities.
The Kudankulam Nuclear Power Plant, India’s largest atomic energy facility, has become the subject of a security incident involving the unauthorized disclosure of internal files. A group identified as World Leaks reportedly posted a collection of documents on the dark web, which allegedly includes facility blueprints, supplier information, inspection records, and control room layouts. These documents cover a period from 2016 to 2025, raising questions about the security of information related to critical national infrastructure.
Reliance Group and Third-Party Server Breach
Reliance Infrastructure, a contractor involved in the plant’s construction, has acknowledged a partial data breach. According to company communications, the incident occurred on a server managed by third-party provider Yotta. While Yotta reportedly identified and stopped suspicious activity on May 29, 2026, the company later confirmed that external actors had made claims regarding the theft of data stored on the server. Reliance Group stated that it has officially informed government authorities about the incident, though the company has not provided a full breakdown of the specific files that were accessed.
Official Investigations and Security Oversight
The Nuclear Power Corporation of India (NPCIL), the state-owned body responsible for the plant's operations, is working alongside Reliance Infrastructure and the Indian Computer Emergency Response Team (CERT-In) to assess the situation. The investigation is focused on determining the extent of the compromised data and evaluating any potential risks to the facility’s operations. While the nature of the information involved is sensitive, authorities are expected to assess whether the breach impacts the operational security of the plant or primarily concerns administrative and contractual documentation.
Past Cybersecurity Incidents
This is not the first time the Kudankulam facility has been associated with cybersecurity concerns. In 2019, malware was identified on an administrative network at the plant. At that time, NPCIL issued statements clarifying that the plant's critical nuclear control systems remained isolated and were not affected by the incident. India’s critical infrastructure has increasingly become a target for cyber threats, placing a renewed focus on the data security practices of private contractors and third-party service providers. Investors and stakeholders are likely to monitor the findings of the current investigation, as such incidents can lead to stricter regulatory requirements for cybersecurity compliance and increased operational costs for contractors involved in sensitive national projects.