TCP Vulnerability in Linux Kernel Affecting Network Performance

CVE-2026-80847

What is CVE-2026-80847?

A vulnerability in the Linux Kernel's TCP implementation could allow an attacker to manipulate the maximum segment size (MSS) to undesirably low values. This flaw arises when the TCP stack processes route-derived ADV_MSS values that deviate from expected norms, potentially causing the effective MSS to drop to zero. By introducing a helper function that clamps the advertised maximum segment size to a minimum threshold, this issue can be mitigated, ensuring stable and reliable network communications.

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