VMXNET3

Critical Vulnerabilities Patched in VMware Workstation and Fusion Allowing Host Code Execution

Broadcom has disclosed two vulnerabilities in VMware Workstation and VMware Fusion rated as critical and important respectively. CVE-2026-59346 is an integer overflow flaw in the VMXNET3 virtual network adapter that can be exploited by a local administrator inside a virtual machine to execute arbitrary code on the host system, carrying a CVSS v3.1 base score of 9.3. CVE-2026-59347 is a stack-based buffer overflow in the HGFS file system that permits code execution on the host as the VMX process with a CVSS score of 8.1. Both issues were privately reported and affect users who run virtual machines with local administrative privileges. The flaws have been addressed in VMware Workstation 26H1u1 and VMware Fusion 26H1u1, and Broadcom urges immediate updates via advisory VMSA-2026-0007.

Broadcom Patches Five Critical VMware Vulnerabilities Including CVSS 9.8 Authentication Bypass

Broadcom has released fixes for five vulnerabilities across multiple VMware products that could enable authentication bypass, remote code execution, and virtual machine escapes. The most severe issue, CVE-2026-59309 with a CVSS score of 9.8, resides in the VMware Directory Service component of vCenter and allows an attacker with network access to bypass authentication entirely. Successful compromise of vCenter grants control over hosts, virtual machines, networks, and storage, posing severe risks to enterprise environments. A second critical flaw, CVE-2026-47876, affects the VMXNET3 virtual adapter in ESX and permits an attacker with administrative privileges inside a guest VM to perform an out-of-bounds write and execute code on the hypervisor host. Additional patches address an unauthorized memory read in ESX, Workstation, and Fusion, along with insufficient logging that could conceal administrative actions. No workarounds exist, and administrators must apply the specified updates to vCenter, ESX, Cloud Foundation, Workstation, and Fusion.