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.

Security researchers say Microsoft customers should take immediate action to defend against the ongoing cyberattacks, and must assume they have already been compromised.

Critical zero-day vulnerabilities in Microsoft SharePoint, tracked as CVE-2025-53770 and CVE-2025-53771, have been actively exploited since at least July 18th, with no patch available and at least 85 servers already compromised worldwide.