CVE intelligence

CVE-2026-31609

Vulnerability intelligence

Published Apr 24, 2026Sources checked Nov 12, 2026

9.8CRITICALCVSS out of 10

What this means

Review the available evidence

CVE-2026-31609 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.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Sep 25, 2026

CBL-Mariner Releases Release Notes

Vendor-listed releases

6.6.134.1-2

CISA KEVNot listedBased on the latest collected catalog

EPSS0.5%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-31609?

In the Linux kernel, the following vulnerability has been resolved:

smb: client: avoid double-free in smbd_free_send_io() after smbd_send_batch_flush()

smbd_send_batch_flush() already calls smbd_free_send_io(), so we should not call it again after smbd_post_send() moved it to the batch list.

Source: NVD