What’s Vulnerable › Vulnerabilities

CVE-2025-40158: ipv6: use RCU in ip6_output()

• Severity: high (CVSS 8.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-11-12 · updated 2026-10-30

Description

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().

Affected products

• Linux: 4.13 — fixed in 6.18

How to fix

Upgrade to a fixed version: Linux 6.18. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/0393f85c3241c19ba8550f04a812e7d19f6b3082
• https://git.kernel.org/stable/c/11709573cc4e48dc34c80fc7ab9ce5b159e29695
• https://git.kernel.org/stable/c/423895685f367b5a0a956bd14b02df0192bded4c
• https://git.kernel.org/stable/c/4549ce1057363c8dc072f40c6aa591c279eafed2
• https://git.kernel.org/stable/c/92803b826e40e49a5e8a6e208f4b4574e9d19426

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