New "Bad Epoll" Linux Kernel Flaw Lets Unprivileged Users Gain Root, Hits Android

Bad Epoll (CVE-2026-46242) is a use-after-free bug (a flaw where code tries to access memory that has already been freed) in the Linux kernel that allows ordinary users to gain root access on Linux desktops, servers, and Android devices. The vulnerability exists in the epoll feature, which programs use to monitor multiple files or network connections at once, and a researcher named Jaeyoung Chung created a working attack that succeeds about 99% of the time by carefully timing the exploitation of a very narrow window where two parts of the kernel interfere with each other.