Fragnesia (CVE-2026-46300): Frequently asked questions about new Linux Kernel XFRM ESP-in-TCP privilege escalation

Tenable RSO documents Fragnesia (CVE-2026-46300), a high-severity Linux kernel XFRM ESP-in-TCP local privilege escalation disclosed May 13 with a public proof-of-concept; the flaw allows local users to gain root via page-cache writes, affects many mainstream distributions, has an estimated CVSSv3 of 7.8, and was addressed by a kernel patch (with module-blacklist mitigation available) though no active exploitation has been reported.