CVE-2016-9777: KVM in the Linux kernel before 4.8.12, when I/O APIC is enabled, does not properly restrict the VCPU index,...

Security readout for executives and security teams

This is a KVM virtualization flaw in Linux kernels before 4.8.12. A user inside a guest VM could potentially crash the host or gain host-level privileges when I/O APIC is enabled. The business concern is strongest for shared or untrusted virtualization environments. Exposure is likely limited to Linux KVM hosts running kernels before 4.8.12 with I/O APIC enabled, especially where guest users are not fully trusted. The bundle does not identify affected distributions or vendor-specific package versions. Treat as high priority for virtualization infrastructure. Guest-to-host privilege gain can affect isolation, and host crashes can disrupt multiple workloads. Patch scheduling should focus first on shared KVM platforms and untrusted guest environments. Mitigation focus: Update affected Linux KVM hosts to kernel 4.8.12 or a vendor backported fix.; Check distribution vendor guidance for exact fixed package versions.; Prioritize shared virtualization hosts and systems running untrusted guest workloads..

Prepared

Jun 13, 2026, 12:51 UTC (UTC+00:00)

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