Microsoft SharePoint Zero-day Attack

FortiGuard Labs reports active, widespread exploitation of a chained SharePoint zero-day vulnerability chain (ToolShell) that combines CVE-2025-49704 and CVE-2025-49706 into new variants (CVE-2025-53770 and CVE-2025-53771); Microsoft and other vendors have observed Chinese nation-state activity (Linen Typhoon, Violet Typhoon) and abuse for ransomware (4L4MD4R), with multiple advisories, IOCs, and patches released—organizations should immediately apply updates and engage incident response as needed.