Microsoft has pointed the finger at three Chinese nation-state actors for exploiting the SharePoint vulnerabilities. Here's what we know about the security flaws and how to guard against future attacks.

NEW YORK (AP) — Microsoft has issued an emergency fix to close off a vulnerability in Microsoft’s SharePoint software that hackers have exploited to carry out widespread attacks on businesses and at least some federal agencies.

The cybersecurity vendor has also classified it as a high-severity, high-urgency threat, urging organizations running on-premises Microsoft SharePoint servers to apply the necessary patches with immediate effect, rotate all cryptographic material, and engage in incident response efforts.