July 23 (Reuters) - A U.S. Department of Energy

spokesperson said that on July 18 a Microsoft

SharePoint zero-day vulnerability impacted its systems,

including those of the National Nuclear Security Administration,

which oversees the nation's nuclear weapons stockpile.

"The department was minimally impacted due to its widespread

use of the Microsoft M365 cloud and very capable cybersecurity

systems. A very small number of systems were impacted. All

impacted systems are being restored," the department said in an

emailed response to Reuters on Wednesday.