Published Aug 11, 2026Sources checked Oct 28, 2026
5.5MEDIUMCVSS out of 10
What this means
Review the available evidence
CVE-2026-72971 and is rated Medium severity with a CVSS score of 5.5. 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 KB5121000.
Vendor-listed releases
10.0.28000.2704
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-2026-72971?
Improper link resolution before file access ('link following') in Windows Container Isolation FS Filter Driver (unionfs.sys) allows an authorized attacker to perform tampering locally.