A public proof of concept is now available for CVE-2026-59346, a critical integer overflow flaw in VMware’s VMXNET3 virtual network adapter, released by 0xCyberstan.
The flaw can allow an attacker with administrative access inside a guest virtual machine to execute code on the host. However, the published PoC shows a host process crash, not a working code-execution exploit.
Broadcom rates the vulnerability at 9.3 on the CVSSv3 scale and patched it in VMware Workstation and Fusion 26H1u1, released on September 3, 2026.
Its advisory lists Workstation and Fusion versions 25H2 and 26H1 as affected. The vendor security advisory states that no workaround is available.
The flaw sits in the TCP Segmentation Offload, or TSO, processing path within the host’s VMware-VMX process. TSO splits a large network packet into smaller segments. The vulnerable routine calculates how much memory those segments need by multiplying the segment count by the space required for each…
