CVE-2026-64286

A flaw was found in the Linux kernel's Kernel-based Virtual Machine (KVM) for arm64 architecture. The flush_hyp_vcpu() function, responsible for copying the host virtual CPU (vCPU) context, does not properly clear a specific internal pointer (__hyp_running_vcpu). This oversight allows a host to provide a value that is then improperly accessed (dereferenced) at Exception Level 2 (EL2), potentially leading to arbitrary memory access within the hypervisor. This could allow a malicious host to compromise the integrity or availability of the hypervisor.

This vulnerability is classified as having a Moderate severity because exploitation requires local privileges on an ARM64 system running protected KVM mode, preventing remote unauthenticated attacks. In typical Red Hat Enterprise Linux deployments, Protected KVM is not enabled by default and hardware virtualization requires specific platform support and configuration. Under these conditions, an attacker must already possess sufficient access on the host to interact with the virtualization subsystem, which restricts the potential impact to environments actively executing protected guest instances.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.