Published Sep 11, 2026Sources checked Oct 31, 2026
9.3CRITICALCVSS out of 10
What this means
Review the available evidence
CVE-2026-89448 and is rated Critical severity with a CVSS score of 9.3. 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
EPSS0.1%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-89448?
In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Force requesting ACS when tboot is enabled
Currently the conditions of requesting ACS in detect_intel_iommu() don't include tboot, leading to a possible misconfiguration with ACS disabled (e.g. due to user opts) while iommu is later forced on by tboot_force_iommu().