Published Sep 25, 2026Sources checked Nov 12, 2026
7.5HIGHCVSS out of 10
What this means
Review the available evidence
CVE-2026-97523 and is rated High severity with a CVSS score of 7.5. 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: Oct 21, 2026
Release Notes
Vendor-listed releases
6.6.158.1-1
CISA KEVNot listedBased on the latest collected catalog
EPSS0.7%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-97523?
In the Linux kernel, the following vulnerability has been resolved:
mptcp: close race between scheduler and state change
The mptcp scheduler may race with subflow sockets state change: data transmission on the selected socket may fail and a later release could try to use mss_now reset to 0 for a divide operation.
Address the issue by explicitly checking for the critical scenario.