IPv4 Header Parsing Vulnerability in Linux Kernel

CVE-2026-43037

What is CVE-2026-43037?

A vulnerability in the Linux kernel's handling of IPv4 headers can lead to potential security risks. Specifically, the function ip4ip6_err() utilizes a cloned socket buffer (skb) with callback data (cb[]) that has been modified by the IPv6 processing path. This mismatch can allow attackers to exploit the system by manipulating header information, leading to memory corruption. The vulnerability has been addressed by clearing the skb2->cb[] field and reinforcing IPv4 header validation to ensure proper data handling and system integrity.

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