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 is issuing 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.

M icrosoft has released two emergency patches to address zero-day vulnerabilities that have been found in SharePoint RCE. Actively exploited in attacks, the two flaws (tracked as CVE-2025-53770 and CVE-2025-53771) are both “ToolShell” attacks that compromise services and that build on flaws that were fixed as part of July’s Patch Tuesday updates.