A newly disclosed Linux kernel vulnerability called Bad Epoll lets an ordinary user with no special privileges take full control of a machine as root, and it affects Linux desktops, servers, and Android. Tracked as CVE-2026-46242, the flaw is a use-after-free in epoll, a core Linux feature for watching many files or connections at once that programs and browsers rely on and cannot simply turn off. Two parts of the kernel try to free the same object at once, letting an attacker corrupt kernel memory and climb to root. It is a race-condition bug, harder to exploit than recent deterministic Linux flaws, but a working exploit exists and a fix is available.
Researcher Hyunwoo Kim disclosed Dirty Frag yesterday after an unrelated third party broke the embargo five days early. The flaw chains two Linux kernel page-cache write bugs (xfrm-ESP and RxRPC) to give any local user root access on every major distribution - Ubuntu, RHEL, CentOS Stream, AlmaLinux, openSUSE Tumbleweed, Fedora. Like Dirty Pipe and last week's Copy Fail, it's a deterministic logic bug with no race condition required and no kernel panic on failure. PoC is public on GitHub. The ESP variant patch was merged into the netdev tree on May 7 but distribution kernels remain unpatched. No CVE assigned yet because the embargo broke early.