Linux Kernel Gets a Fix for a Flaw that Enabled Attackers to Escape VMs

PwnEscape Exposes Linux Kernel Networking Flaw That Shatters VM Isolation

A critical Linux kernel bug called PwnEscape (CVE-2026-99999) lets VM guests read host memory and achieve full escape in tests. Found during Vercel's $1M challenge, the networking flaw affects broad cloud infrastructure. Patches are available across stable branches. Providers and operators must update promptly.

Linux kernel gets a fix for a flaw that enabled attackers to escape VMs

The Linux kernel’s networking stack was found vulnerable to a guest-to-host escape attack, in which an attacker operating inside a virtual machine (VM) could cross the isolation boundary and access the underlying host. Dubbed PwnEscape and tracked as CVE-2026-99999, a flaw allowed guest-controlled packet metadata to trigger a write that changes an IPv4 header after the kernel has already processed it. That flaw could be chained with additional e…

Critical Linux Kernel Flaw Lets Attackers Escape Virtual Machines and Take Control of Hosts

A critical flaw in the Linux kernel may allow an attacker-controlled virtual machine (VM) to breach its isolation boundary and impact the host system. This vulnerability, identified as CVE-2026-99999 and referred to as PwnEscape by researcher Paulos Yibelo, originates from the Linux networking code rather than a specific hypervisor. Paulos Yibelo demonstrated a technique that […]

Critical PwnEscape Linux Kernel Vulnerability Lets Guest VMs Read Host Memory

A newly disclosed critical flaw in the Linux kernel allows code inside a virtual machine to read memory on the host computer it runs on. A researcher demonstrated the leak against Vercel's live cloud sandboxes, and Vercel confirmed it. The flaw, now tracked as CVE-2026-99999 and nicknamed PwnEscape, is in the Linux kernel's networking code, not in any one cloud's setup, so it reaches the shared