AI-Found Linux Kernel Flaw Gives Local Users Root, and Can Break a Guest Out to the Host

A critical vulnerability tracked as CVE-2026-74580 and named 'Vghost' has been discovered in Linux's vhost subsystem. The flaw allows local users to read and write kernel memory arbitrarily, enabling privilege escalation to root. It affects nearly a decade's worth of Linux kernel versions. In virtualization environments, the bug can be exploited by an untrusted virtual machine to write to the host's memory and hijack the hypervisor process, effectively breaking out of the guest VM. The vulnerability was discovered by Tencent Zhuque Lab using AI-assisted techniques. The combination of local privilege escalation and VM escape capabilities makes this a severe security risk for both standalone Linux systems and virtualized infrastructures.