CVE intelligence

CVE-2026-80586

Vulnerability intelligence

Published Aug 26, 2026Sources checked Sep 12, 2026

9.8CRITICALCVSS out of 10

What this means

Review the available evidence

CVE-2026-80586 and is rated Critical severity with a CVSS score of 9.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

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-2026-80586?

In the Linux kernel, the following vulnerability has been resolved: mptcp: options: reset DSS fields in case of unexpected size A remote peer could send a malformed DSS with a wrong size, followed by another DSS or MPC + Data. In this case, the first suboption will be ignored, but leaving some fields written, which could lead to inconsistency or access uninitialized data. Explicitly reset the fields that could have been modified in case of unexpected size.