The newly discovered flaw in Microsoft's SharePoint software has allowed hackers to target dozens of companies and organizations. Only a partial fix has been issued.

Microsoft issued an emergency fix to close off a vulnerability in its SharePoint software that hackers have exploited to carry out widespread attacks on businesses and at least some federal agencies.

Microsoft has issued an alert about “active attacks” on server software used by government agencies and businesses to share documents within organizations, and recommended security updates that customers should apply immediately.

Microsoft said the company has been "coordinating closely with CISA, DOD Cyber Defense Command, and key cybersecurity partners around the world throughout our response."

Microsoft Corp.’s server software is under attack from unidentified hackers, with cybersecurity analysts warning of widespread security breaches across the globe.