In the Linux kernel, the following vulnerability has been resolved: ipv6: use RCU protection in ip6_default_advmss() ip6_default_advmss() needs rcu protection to make sure the net structure it reads does not disappear.
Upstream advisory: https://lore.kernel.org/linux-cve-announce/2025022605-CVE-2025-21765-4d5e@gregkh/T