Linux Kernel Vulnerability Affecting Netlink Multicast Functionality

CVE-2026-31664

What is CVE-2026-31664?

A vulnerability within the Linux kernel's networking stack permits leakage of kernel heap memory contents due to uninitialized padding bytes in the struct xfrm_user_polexpire. The build_polexpire() function neglects to clear these trailing bytes, leading to exposure of sensitive data to user space applications listening on the XFRMNLGRP_EXPIRE netlink multicast group. This issue can potentially be exploited to glean information about the kernel's memory state, presenting a risk of unintended data exposure.

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