CVE intelligence

CVE-2025-40158

Vulnerability intelligence

Published Nov 12, 2025Sources checked Oct 3, 2026

8.1HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2025-40158 and is rated High severity with a CVSS score of 8.1. 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

Release Notes

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-2025-40158?

In the Linux kernel, the following vulnerability has been resolved: ipv6: use RCU in ip6_output() Use RCU in ip6_output() in order to use dst_dev_rcu() to prevent possible UAF. We can remove rcu_read_lock()/rcu_read_unlock() pairs from ip6_finish_output2().