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 has issued an urgent alert after hackers began exploiting a critical SharePoint Server flaw. The FBI and CISA are responding as agencies and businesses are targeted.

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