U.S. Nuclear Agency Breached in Microsoft SharePoint Hack
The U.S. National Nuclear Security Administration (NNSA), the agency responsible for maintaining and designing the nation’s nuclear weapons, was among the organizations affected by a recent cyberattack exploiting a vulnerability in Microsoft’s SharePoint document management software. The breach was reported on July 22, 2025, citing anonymous sources familiar with the matter. While the NNSA has not publicly commented on the incident, it is believed that no sensitive or classified information was compromised during the attack.
The breach is part of a broader wave of cyberattacks targeting organizations that use on-premises versions of Microsoft SharePoint. Hackers exploited a zero-day vulnerability in the software, allowing them to gain unauthorized access to systems and potentially steal sensitive data. Microsoft has acknowledged the issue and released security updates to address the vulnerability. The company has urged organizations to apply these updates promptly to protect against potential exploits.
The U.S. Department of Energy, which oversees the NNSA, stated that the impact of the breach was minimal due to the department’s extensive use of Microsoft 365 cloud services and robust cybersecurity systems. The department emphasized that only a small number of systems were affected and that efforts are underway to restore any compromised systems.
The incident underscores the ongoing challenges organizations face in securing their systems against sophisticated cyber threats. It also highlights the importance of timely software updates and the need for comprehensive cybersecurity measures to protect critical infrastructure.
