Linux Kernel Vulnerability in IPv6 Flow Label Management

CVE-2026-31680

What is CVE-2026-31680?

A vulnerability in the Linux kernel affects the management of IPv6 flow labels, where improper handling of memory can lead to a race condition. Specifically, during the reading of flow labels through the /proc/net/ip6_flowlabel interface, a concurrent reader may attempt to access freed memory, leading to potential crashes. The issue arises when exclusive flowlabels are freed prematurely, exposing a race scenario before proper garbage collection occurs. A fix has been implemented to ensure that the memory for option states is maintained until they are no longer accessible, aligning their lifecycle with that of the enclosing flowlabel.

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