CVE-2026-98440

A flaw was found in the Linux kernel's Kernel-based Virtual Machine (KVM) subsystem on ARM64 architectures. In nested virtualization configurations, shadow memory management structures are prematurely freed during shadow page flushes while other parts of the system may still reference them. A local user with permissions to run virtual machines can exploit this flaw to trigger a use-after-free condition, resulting in a denial of service (DoS) via a system crash or potential memory corruption.

This vulnerability is rated as having a Moderate impact because it requires local access with privileges to manage virtual machines and is restricted to ARM64 environments utilizing nested virtualization, an uncommon deployment mode. Exploitation depends on precise timing during hypervisor shadow memory cleanup operations, reducing reliability. An attacker successfully triggering this flaw can crash the host kernel or cause localized memory corruption, but cannot achieve direct remote code execution.

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.