The TCP stack in the Linux kernel 3.x does not properly implement a SYN cookie protection mechanism for the case of a fast network connection, which allows remote attackers to cause a denial of service (CPU consumption) by sending many TCP SYN packets, as demonstrated by an attack against the kernel-3.10.0 package in CentOS Linux 7. NOTE: third parties have been unable to discern any relationship between the GitHub Engineering finding and the Trigemini.c attack code.
Severity
CVSS 3.1
7.5 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
24% chance of exploitation in the next 30 days; higher than 97% of CVEs (scores of 2026-10-31)