18-Year-Old Linux SCTP Flaw Could Let Local Users Gain Root and Escape Containers

An 18-year-old use-after-free vulnerability in the Linux SCTP networking stack allows local attackers to gain full root access on a host and potentially escape containers. Tracked as CVE-2026-64564 and named SCTPhantom, the flaw was recently addressed in stable kernel versions 7.1.6, 6.18.42, 6.12.101, and 6.6.148. The bug, present since 2008, stems from improper handling of dynamic address reconfiguration in SCTP connections, allowing malicious actors to manipulate pointers leading to arbitrary code execution. While no public exploits have emerged yet, Tencent researchers demonstrated successful container escapes under specific configurations. System administrators using older kernels with active SCTP support should upgrade immediately.