NVD Vulnerability Detail
Search Exploit, PoC
CVE-2026-64172
Summary

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.

Publication Date July 20, 2026, 1:17 a.m.
Registration Date July 20, 2026, 4:20 a.m.
Last Update July 21, 2026, 12:17 a.m.
CVSS3.1 : HIGH
スコア 7.1
Vector CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
攻撃元区分(AV) ローカル
攻撃条件の複雑さ(AC)
攻撃に必要な特権レベル(PR) 不要
利用者の関与(UI) 不要
影響の想定範囲(S) 変更あり
機密性への影響(C) なし
完全性への影響(I) なし
可用性への影響(A)
Related information, measures and tools
Common Vulnerabilities List