Advisory Details

March 16th, 2026

(Pwn2Own) VMware ESXi VMXNET3 Integer Overflow Local Privilege Escalation Vulnerability

ZDI-26-189
ZDI-CAN-27157

CVE ID CVE-2025-41236
CVSS SCORE 8.2, AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
AFFECTED VENDORS VMware
AFFECTED PRODUCTS ESXi
VULNERABILITY DETAILS

This vulnerability allows local attackers to escalate privileges on affected installations of VMware ESXi. An attacker must first obtain the ability to execute high-privileged code on the target guest system in order to exploit this vulnerability.

The specific flaw exists within the implementation of the VMXNET3 virtual device. The issue results from the lack of proper validation of user-supplied data, which can result in an integer overflow before allocating a buffer. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the hypervisor.

ADDITIONAL DETAILS VMware has issued an update to correct this vulnerability. More details can be found at:
https://support.broadcom.com/web/ecx/support-content-notification/-/external/content/SecurityAdvisories/0/35877
DISCLOSURE TIMELINE
  • 2025-05-21 - Vulnerability reported to vendor
  • 2026-03-16 - Coordinated public release of advisory
  • 2026-03-16 - Advisory Updated
CREDIT Nguyen Hoang Thach of STAR Labs SG Pte. Ltd.
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