Fragnesia Linux Vulnerability Let Attackers Gain Root Privileges – PoC Released

Fragnesia is a critical Linux kernel vulnerability (a Dirty Frag family bug) that lets any local unprivileged user escalate to root without a race by causing the kernel to treat spliced file pages as ESP ciphertext and XOR a chosen AES-GCM keystream byte into the page cache; the in-memory /usr/bin/su can be modified to spawn root shells until the cache is flushed. A public proof-of-concept exists, the upstream patch was submitted but systems before May 13, 2026 remain vulnerable, and immediate mitigation steps (unloading ESP modules and dropping caches or rebooting) are recommended.