New “Bad Epoll” 0-Day Vulnerability Allows Root Access on Linux Servers and Android Devices

**Executive Summary:** The report describes a newly disclosed Linux kernel privilege-escalation vulnerability named "Bad Epoll" (CVE-2026-46242), a use-after-free in the epoll subsystem that can be reliably exploited to obtain root on Linux and Android (including from within Chrome's renderer sandbox); the exploit uses careful race-window widening, cross-cache manipulation and ROP to achieve high reliability, and remediation requires applying the upstream kernel patch since epoll cannot be disabled.