Overview

VMware disclosed four critical vulnerabilities (CVE-2025-41236 to CVE-2025-41239) affecting multiple products including ESXi, Workstation, Fusion, Tools, and Cloud Foundation.

These were discovered during the Pwn2Own Berlin 2025 contest and pose serious risks such as VM escape, host-level code execution, and information leakage.

Vulnerability Breakdown

CVE-2025-41236 – Integer Overflow in VMXNET3 Adapter

• CVSS Score: 9.3

• Impact: Allows a guest VM admin to execute arbitrary code on the host.

• Risk: Critical in cloud, VDI, and MSP environments

CVE-2025-41237 – Integer Underflow in VMCI Device

• CVSS Score: 9.3

• Impact: Enables guest VM admin to run code as the VMX host process.

• Risk: High risk of VM escape1.

CVE-2025-41238 – Heap Overflow in PVSCSI Controller

• CVSS Score: 9.3

• Impact: Code execution on host in certain configurations.

• Risk: Major risk for misconfigured or legacy VMs 1.

CVE-2025-41239 – Uninitialised Memory in vSockets

• CVSS Score: 7.1

• Impact: Memory leakage from host to guest.

• Risk: Medium, but notable in sensitive environments 2.

Affected VMware Products

• VMware ESXi

• VMware Workstation

• VMware Fusion VMware Tools

• VMware Cloud Foundation (ESX component)

• VMware vSphere Foundation (ESX component)

• VMware Telco Cloud Platform VMware Telco Cloud Infrastructure

Vulnerability Breakdown by Product

Recommendations

2 hours to patch version 8 or 4 hours to upgrade to the latest version of 9 with potential downtime.

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