Critical PwnEscape Vulnerability in Linux Kernel Allows VM-to-Host Memory Access

A critical vulnerability in the Linux kernel, tracked as CVE-2026-99999 and nicknamed PwnEscape, allows code running inside a virtual machine to read memory on the host computer. The flaw is located in the Linux kernel's networking code rather than in any specific cloud provider's configuration. A researcher demonstrated the vulnerability against Vercel's live cloud sandboxes, and Vercel confirmed the issue. The vulnerability affects shared infrastructure due to its presence in the core Linux kernel networking code.