Use-After-Free Vulnerability in Linux Kernel Affecting Multicast Group Processing

CVE-2026-53275

What is CVE-2026-53275?

A vulnerability exists in the Linux kernel that can lead to a use-after-free condition when processing Multicast Listener Discovery (MLD) queries. The issue arises when the kernel retrieves a pointer to the multicast group address during the initial packet parsing. If the socket buffer (skb) header is reallocated without reloading this pointer, it can result in dereferencing invalid memory, leading to potential exploitation. The recommended fix involves copying the multicast group address during the initial parse to prevent the chance of a use-after-free error. This vulnerability underscores the importance of careful memory management in kernel space.

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