Published Oct 13, 2026Sources checked Oct 21, 2026
4.6MEDIUMCVSS out of 10
What this means
Review the available evidence
CVE-2026-88209 and is rated Medium severity with a CVSS score of 4.6. 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: Oct 13, 2026
Install KB5002927.
Vendor-listed releases
16.0.20326.20190
CISA KEVNot listedBased on the latest collected catalog
EPSS0.4%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-88209?
Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Office SharePoint allows an authorized attacker to perform spoofing over a network.