CVE-2026-46300: Fragnesia Linux Kernel Flaw Grants Root via Page Cache Corruption

Local privilege-escalation bugs remain especially dangerous when they turn an ordinary user foothold into immediate root access. The CVE-2026-46300 vulnerability, nicknamed Fragnesia, is a high-severity Linux kernel flaw in the XFRM ESP-in-TCP subsystem that allows an unprivileged local attacker to write arbitrary bytes into the page cache of read-only files and escalate privileges. Public reporting assigns it a CVSS score of 7.8 and links it to the same broader bug class as…