Published Aug 11, 2026Sources checked Oct 28, 2026
8.8HIGHCVSS out of 10
What this means
Review the available evidence
CVE-2026-70321 and is rated High severity with a CVSS score of 8.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
What to do next
Remediation and response
Microsoft Security Response Center guidance
Vendor revision: Aug 11, 2026
Install KB5002893.
Vendor-listed releases
16.0.19725.20522
CISA KEVNot listedBased on the latest collected catalog
EPSS1.7%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-70321?
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.