CVE-2009-4031: The do_insn_fetch function in arch/x86/kvm/emulate.c in the x86 emulator in the KVM subsystem in the Linux...

Security readout for executives and security teams

CVE-2009-4031 affects Linux KVM virtualization on x86. A user inside a guest operating system could trigger abnormal KVM instruction emulation behavior and cause increased scheduling latency on the host. The business impact is availability degradation for virtualization hosts, not data theft or privilege escalation based on the provided sources. Exposure is most relevant to organizations running older Linux KVM hosts on x86, especially where untrusted or semi-trusted users control guest operating systems. Modern supported kernels are unlikely to be affected, but legacy virtualization estates should be checked. Treat as a legacy virtualization availability issue. Prioritize if the organization still runs old KVM hosts or allows less-trusted tenants on shared infrastructure. If all KVM hosts use supported, updated kernels, urgency is low. Mitigation focus: Identify KVM hosts running Linux kernels older than 2.6.32-rc8-next-20091125.; Apply vendor kernel updates referenced by your Linux distribution.; Review SUSE, Fedora, Red Hat, and upstream kernel guidance for applicable packages..

Prepared

Jun 28, 2026, 14:15 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.