CVE-2026-64513

A flaw was found in the Linux kernel's Kernel-based Virtual Machine (KVM) for x86 architectures. When the apic_update_ppr() function does not find a deliverable interrupt, it fails to recompute the CR8 intercept, leading to a stale Task Priority Register Threshold (TPR_THRESHOLD). This issue can cause a virtual machine (VM) entry failure with a hardware error (0x7) on older platforms or in nested virtualization environments that do not support virtual-interrupt delivery, such as Hyper-V.

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.