The Linux kernel’s SCTP UDP tunneling mechanism left socket objects and associated kernel resources open when a network namespace was torn down. This oversight caused resource leaks—file descriptors, memory, and other kernel objects remained allocated, increasing the system’s resource footprint over time. Repeated creation and destruction of namespaces could cumulatively exhaust kernel resources, making the system unresponsive and enabling a denial‑of‑service condition.

Any Linux kernel system that enables SCTP UDP tunneling by setting the sysctl value net.sctp.udp_port to a non‑zero number is affected. The flaw is independent of a particular kernel release, as it persists until the patch that closes the sockets during namespace teardown is applied.

Exploitation requires the ability to create and destroy network namespaces, which is typically limited to privileged users or users with the CAP_SYS_ADMIN capability. Based on the description, it is inferred that the attacker must have local or privileged access to perform the exploit. The EPSS score is < 1% and the vulnerability is not listed in the CISA KEV catalog, indicating no known widespread exploitation. The CVSS score of 9.8 indicates high severity. Nevertheless, for systems that enable SCTP UDP tunneling, the risk remains significant because the attack surface, while restricted to privileged actions, can lead to severe availability degradation.