CVE-2026-64172: Linux Kernel

High severity, CVSS 7.1. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Disable AVIC IPI virtualization on Hygon Family 18h (erratum #1235) Hygon Family 18h CPUs are derived from AMD Family 17h (Zen1) silicon and share the same erratum #1235: hardware may read a stale IsRunning=1 bit during ICR write emulation and silently fail to generate an AVIC_IPI_FAILURE_TARGET_NOT_RUNNING VM-Exit on the sending vCPU. The absence of the VM-Exit causes KVM to miss the required wakeup of blocking target vCPUs, leading to hung vCPUs and unbounded delays in guest execution. Extend the existing AMD Family 17h erratum #1235 workaround to also cover Hygon Family 18h. With IPI virtualization disabled, KVM never sets IsRunning=1 in the Physical ID table, so every non-self IPI generates a VM-Exit and is correctly emulated.

Affected products

• Linux Linux Kernel: from 6.17, before 6.18.34 (fixed in 6.18.34); from 6.19, before 7.0.11 (fixed in 7.0.11); version 7.1 only

Published 2026-07-19. Last modified 2026-08-13.