# CVE-2026-64172 — Linux

> As of 2026-07-20, CVE-2026-64172 is a HIGH-severity vulnerability in Linux, CVSS v3.1 7.1, EPSS 0.1% (6.2th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-64172 as of 2026-07-20; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-07-20

## What is CVE-2026-64172?

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.

Its CVSS v3 base vector states that the flaw requires local access to the host, needs no prior authentication, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 78 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.1 — HIGH (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H`)
- **EPSS (FIRST):** 0.1% probability of exploitation in the next 30 days, higher than 6.2% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 3.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-07-19, last modified 2026-07-20

## Is CVE-2026-64172 being exploited?

It currently carries a trending score of 31 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [Linux](https://intel.threadlinqs.com/vendors/linux): Linux

## How to fix CVE-2026-64172

No vendor patch reference has been recorded for CVE-2026-64172 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-64172

No threat campaign in the Threadlinqs corpus currently references CVE-2026-64172, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-07-21. This product uses the NVD API but is not endorsed or certified by the NVD.

**Other references**

- [git.kernel.org](https://git.kernel.org/stable/c/94ade38f317ea086a181db0e6b69c574b3b70a5e)
- [git.kernel.org (9560e6fee887a9594a89fa265b5b9c79b1591803)](https://git.kernel.org/stable/c/9560e6fee887a9594a89fa265b5b9c79b1591803)
- [git.kernel.org (9a12fa5213cfc391e0eed63902d3be98f0913765)](https://git.kernel.org/stable/c/9a12fa5213cfc391e0eed63902d3be98f0913765)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-64172
Full detection coverage and IOCs for threats exploiting CVE-2026-64172 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp