CVE-2025-40158
Published Nov 12, 2025
Modified Apr 15, 2026
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().
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References
Frequently Asked Questions
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().
How do I check if I'm vulnerable to CVE-2025-40158? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.