Linux Kernel vhost Subsystem Flaw Enables Privilege Escalation and VM Escape

A flaw in Linux's vhost subsystem lets a local user read and write kernel memory at will and become root across nearly a decade of kernel versions. In one virtualization setup, it lets an untrusted virtual machine write to the host's memory and hijack the program that runs the virtual machine.

The bug is tracked as CVE-2026-74580 and named Vghost. Tencent Zhuque Lab discovered the flaw; Linux kernel maintainers and users are affected. The vulnerability spans kernel versions over nearly a decade. The issue stems from improper handling of vhost memory files in the Linux kernel's vhost subsystem. A local user can exploit the flaw to read and write kernel memory at will, escalate privileges to root, and in virtualization contexts, an untrusted virtual machine can write to the host's memory and hijack the program running the virtual machine.

As of the public report, no confirmed active exploitation in the wild has been confirmed, though the memory-read/write capability could be weaponized for privilege escalation and VM escape. Patches have been released in recent stable kernel releases; administrators are advised to update to the patched kernel version addressing CVE-2026-74580.