Published Aug 26, 2026Sources checked Oct 28, 2026
8.8HIGHCVSS out of 10
What this means
Review the available evidence
CVE-2026-80552 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: Oct 2, 2026
Release Notes
Vendor-listed releases
6.6.157.1-1
CISA KEVNot listedBased on the latest collected catalog
EPSS0.2%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-80552?
In the Linux kernel, the following vulnerability has been resolved:
s390/vfio_ccw: Ensure index for read/write regions are within range
The introduction of the capability chain rightly clamped the region indexes to the range of the capabilities itself, but neglected to do so for the existing read/write regions which should also be enforced.