PoC Exploit Released for Fragnesia Linux Flaw Enabling Root Access

A newly disclosed Linux local privilege escalation vulnerability called "Fragnesia" abuses a logic error in the ESP/XFRM subsystem to write arbitrary data into the kernel page cache (similar to Dirty Pipe), enabling immediate root access. A public PoC targets /usr/bin/su, affects kernels prior to the May 13, 2026 patch, and the report includes mitigation steps (module removal/modprobe blacklisting, applying the kernel patch) and guidance to flush caches or reboot compromised systems.