Linux

Januscape is a Linux KVM/x86 use-after-free that can turn nested virtualization into host-root code execution. Red Hat scores it CVSS 7.8; a host-crash PoC is public, while the full escape exploit remains withheld.

A logic flaw in the Linux kernel's cryptographic subsystem has been hiding since 2017, and it hands root access to any unprivileged user in 732 bytes of Python.