The tech giants have evidence that Chinese hackers are exploiting the new bug, but warned "multiple actors" are also hacking into affected SharePoint systems.

CISA has mandated immediate mitigation for federal agencies, while analysts urge enterprises to accelerate cloud migration and implement live threat detection.

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.