New Linux Kernel Vulnerability Fragnesia Allows Root Privilege Escalation

A new Linux kernel vulnerability nicknamed Fragnesia, tracked as CVE-2026-46300, allows local attackers to escalate privileges to root by exploiting the XFRM ESP-in-TCP subsystem to overwrite sensitive system files. The flaw is similar to recently disclosed vulnerabilities Dirty Frag and Copy Fail, and while a proof-of-concept exploit is now available, there's currently no evidence of real-world attacks. Most Linux distributions are affected and have begun releasing patches, with Microsoft urging organizations to apply updates immediately, especially given that related vulnerabilities have been exploited in the wild.