Microsoft has released security patches for the zero-day vulnerability chain dubbed ToolShell, capable of remote code execution on SharePoint, resulting in the exploitation of at least 54 organizations worldwide.

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.

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.