🟠 High | Source: The Hacker News
A Linux kernel vulnerability dubbed ‘Zapscape’ (CVE-2026-64561) allows an attacker with kernel-level privileges inside a guest virtual machine to break out of KVM isolation and execute arbitrary code on the underlying host. The flaw resides in KVM/x86’s shadow MMU, the component responsible for managing memory translation between guest and host. The risk is most acute in environments where nested virtualisation is exposed to untrusted workloads, such as public cloud or shared infrastructure scenarios.
Security Architect’s Take: Audit your KVM-based infrastructure for any deployments that expose nested virtualisation to tenant or untrusted workloads, and disable it where not strictly required. Prioritise patching Linux kernel packages on all KVM hosts — particularly on bare-metal cloud nodes and on-prem hypervisors — and treat any guest with kernel access as a potential threat until mitigated.
Original advisory: New Zapscape KVM Flaw Could Let Privileged L1 Guest Code Escape to Linux Hosts