Linux Kernel variable initialization flaw enables ESP RCE

CISA added CVE-2026-46300 to the Known Exploited Vulnerabilities catalog. A missing variable initialization in Linux Kernel's socket buffer coalescing can be chained with CVE-2026-109618 and CVE-2026-109619 to implant PHP webshells and execute commands as root. Apply patches immediately per BOD 26-04 guidelines. Federal due date: October 31, 2026.