As part of Black October, researchers are warning that a high-severity Linux kernel privilege escalation flaw is being actively chained with the PHP2SHELL vulnerabilities. Tracked as CVE-2026-46300 and called “Fragnesia,” the flaw stems from a logic defect in the Linux XFRM ESP-in-TCP subsystem that leaves stale page-cache writes exploitable for root access. Public proof-of-concept exploits allow local attackers to execute arbitrary code with root permissions on major Linux distributions running
