CVE-2026-59347 in Workstation
Summary
by MITRE • 10/07/2026
VMware Workstation and Fusion contain a stack-based buffer-overflow vulnerability in HGFS. A malicious actor with local administrative privileges on a virtual machine may exploit this issue to execute code as the virtual machine's VMX process running on the host.
Affected versions: - VMware Workstation: 25H2, 26H1 (fixed in 26H1u1) - VMware Fusion: 25H2, 26H1 (fixed in 26H1u1)
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Analysis
by VulDB Data Team • 10/08/2026
The vulnerability identified within VMware Workstation and VMware Fusion represents a critical stack-based buffer overflow located specifically within the Host-Guest File System HGFS component. This architectural flaw arises from insufficient boundary checks when processing data passed between the virtualized guest environment and the host operating system via shared folders or file synchronization mechanisms. The HGFS service is responsible for facilitating seamless file access across the hypervisor boundary, a feature heavily utilized in development and testing environments where rapid iteration of codebases requires frequent interaction with host resources. When an attacker crafts specific input that exceeds the allocated stack memory limits during this data transfer process, it overwrites adjacent memory locations on the call stack, thereby corrupting control flow structures such as return addresses or exception handlers.
Exploitation of this vulnerability requires a precise set of conditions due to its local nature and privilege requirements. A malicious actor must possess administrative privileges within the guest virtual machine to trigger the vulnerable code path effectively. Once these prerequisites are met, an attacker can execute arbitrary commands by leveraging the overflowed stack data to redirect execution flow into shellcode injected into the process memory. The ultimate impact is severe because the VMX process, which manages the virtual machine's operation on the host system, runs with elevated privileges relative to standard user accounts. Successful exploitation allows the adversary to escape the isolation boundary of the guest OS and achieve remote code execution within the context of the hypervisor management process on the underlying physical or cloud-hosted infrastructure.
From a threat modeling perspective, this vulnerability aligns closely with CWE-121 Stack-based Buffer Overflow, which describes situations where data is written beyond the buffer's allocated memory space due to improper bounds checking. Furthermore, it maps directly to MITRE ATT&CK technique T1059 Command and Scripting Interpreter under lateral movement or privilege escalation vectors, as well as potentially T1610 Tool Delivery if used in conjunction with other exploits for initial access. The ability to execute code as the VMX process effectively grants the attacker control over the host environment, enabling further pivoting into internal networks, exfiltration of sensitive data stored on the host, or persistence mechanisms that survive guest OS reboots and potentially even hypervisor restarts depending on implementation specifics.
Mitigation strategies must prioritize immediate patching to address this critical flaw. Administrators should upgrade VMware Workstation and VMware Fusion to version 26H1u1 or later where the issue has been resolved through rigorous input validation and memory safety improvements within the HGFS module. In environments where upgrading is not immediately feasible, organizations should consider disabling shared folders entirely if they are not strictly necessary for operational workflows. Additionally enforcing strict network segmentation between host systems and guest VMs can limit the blast radius of a potential compromise. Security teams should also monitor for anomalous process creation events involving vmware-vmx.exe or similar hypervisor binaries originating from unexpected user contexts, as this may indicate active exploitation attempts against unpatched instances.