CVE-2026-47876: VMware ESX out-of-bounds write in VMXNET3 adapter

CVE-2026-47876 · Severity: critical · CVSS 9.3 · Published 2026-07-30

VMware ESX is a virtualization platform used to run multiple virtual servers on a single physical machine. A vulnerability in the VMXNET3 virtual network adapter allows a user with administrative control over a single virtual machine to break out of that environment and execute commands on the underlying host server. This could lead to a total compromise of all other virtual machines running on the same physical hardware.

Technologies: VMware Cloud Foundation, VMware ESXi, VMware vSphere Foundation. Vendors: VMware.

Quick answers

Is CVE-2026-47876 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-47876 being exploited in the wild.
How severe is CVE-2026-47876?
Critical severity, with a CVSS score of 9.3, published 30 July 2026.
Which products and versions are affected?
VMware Cloud Foundation 5.x, 9.0.x.x, 9.1.x.x; VMware ESX 8.0 before ESXi80U3k-25595708, 9.0.x.x before ESXi-9.0.2.0100-25595025, 9.1.x.x before ESXi-9.1.0.0200-25557999; VMware ESXi 8.0 before ESXi80U3k-25595708, 9.0.x.x before ESXi-9.0.2.0100-25595025, 9.1.x.x before ESXi-9.1.0.0200-25557999; VMware vSphere Foundation 9.0.x.x, 9.1.x.x.
Is there a fix for CVE-2026-47876?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-47876 attacked?
It is attacked with local access, in an operating system.
Am I affected by CVE-2026-47876?
Check whether you run VMware Cloud Foundation, VMware ESX, VMware ESXi or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

An out-of-bounds write vulnerability (CWE-787) exists in the VMXNET3 virtual network adapter component of VMware ESX. A malicious actor with local administrative privileges on a guest virtual machine can exploit this flaw to escape the virtualized environment and execute arbitrary code on the ESXi host. The vulnerability is specific to the VMXNET3 adapter; other virtual network adapter types are not affected. This issue was reported via Pwn2Own and is addressed in various ESXi 8.0 and 9.x patch releases.

Affected products

  • VMware ESX / ESXi 8.0 before ESXi80U3k-25595708, 9.0.x.x before ESXi-9.0.2.0100-25595025, 9.1.x.x before ESXi-9.1.0.0200-25557999
  • VMware Cloud Foundation 5.x, 9.0.x.x, 9.1.x.x
  • VMware vSphere Foundation 9.0.x.x, 9.1.x.x
  • VMware Telco Cloud Platform 5.0.x, 5.1.x

Timeline

  • 2026-07-29: advisory: Initial publication by Broadcom (VMSA-2026-0006)
  • 2026-07-30: disclosed: NVD publication date

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.