Use-After-Free Vulnerability in Linux Kernel Netfilter Component

CVE-2026-43027

What is CVE-2026-43027?

A use-after-free vulnerability has been identified in the netfilter component of the Linux kernel. This issue arises when the function nf_conntrack_helper_unregister incorrectly passes NULL instead of the actual helper pointer, leading to the improper cleanup of expectations tied to the helper. As a result, when the corresponding helper object is deleted, it can trigger dereferencing of freed memory during subsequent operations. This could lead to instability within the system, and potentially allow for malicious exploitation by accessing previously freed memory, which is a critical concern for maintaining system security.

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