The company released security updates to address these vulnerabilities and strongly urged all users of on-premises SharePoint systems to apply the updates immediately.

At least three China-based hacking teams have been exploiting a previously unknown flaw in Microsoft SharePoint since at least July 7, the company said in a blog post. Why it matters: Microsoft and security researchers didn't uncover the vulnerability until this past weekend,

Microsoft confirmed hackers breached SharePoint servers using a critical zero-day vulnerability. U.S. federal agencies, universities, energy companies, and businesses were hit, highlighting the attack’s vast scale.