New estimates regarding the recently-exploited Microsoft SharePoint vulnerabilities now evaluate that as many as 400 organizations may have been targeted.

Unknown threat actors have breached the National Nuclear Security Administration's network in attacks exploiting a recently patched Microsoft SharePoint zero-day vulnerability chain.

The US agency responsible for maintaining and designing the nation’s cache of nuclear weapons was among those breached by a hack of Microsoft Corp.’s SharePoint document management software, according to a person with knowledge of the matter.