On 3 September 2026 Broadcom published VMSA-2026-0007, a Critical advisory for VMware Workstation and VMware Fusion, the desktop hypervisors many developers and security teams run on their own laptops. It fixes two bugs that let a malicious actor with administrative privileges inside a guest VM execute code on the host.
Both were privately reported, and Broadcom lists no workarounds. The fix is a single release, 26H1u1, for both products. The CVE records were published on 7 October, so some scanners and feeds will only have started flagging these in the last two weeks.
What's affected
| CVE | Component | Impact | CVSSv3 | Affected | Fixed |
|---|---|---|---|---|---|
| CVE-2026-59346 | VMXNET3 virtual network adapter, integer overflow (CWE-190) | Code execution on the host | 9.3 | Workstation and Fusion 25H2, 26H1 | 26H1u1 |
| CVE-2026-59347 | HGFS (shared folders), stack-based buffer overflow (CWE-121) | Code execution as the VM's VMX process on the host | 8.1 | Workstation and Fusion 25H2, 26H1 | 26H1u1 |
The preconditions, from the advisory:
- CVE-2026-59346 needs local administrative privileges on a virtual machine that has a VMXNET3 virtual network adapter.
- CVE-2026-59347 needs local administrative privileges on a virtual machine. The flaw is in HGFS, the Host Guest File System that backs shared folders.
Broadcom credits h4urek with secsys lab and Y² (cameudis), plus Stan S working with TrendAI Zero Day Initiative, for independently reporting CVE-2026-59346, and Yeonghyeon Choi and Tianchu Chen of Tencent Xuanwu Lab for CVE-2026-59347. CISA's enrichment on both CVE records shows no known exploitation.
How to check if you're exposed
The question is which machines run Workstation or Fusion at all, which often is not tracked centrally because the tools are free and installed by individuals.
On macOS, check the Fusion version from the app bundle:
defaults read "/Applications/VMware Fusion.app/Contents/Info.plist" CFBundleShortVersionString
On Windows, query installed programs:
Get-ItemProperty HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\*,
HKLM:\Software\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall\* |
Where-Object DisplayName -like "VMware Workstation*" |
Select-Object DisplayName, DisplayVersion
On Linux hosts:
vmware -v
Then look at what runs inside those VMs. The risk is highest where a guest is less trusted than the host: malware analysis VMs, VMs that run untrusted code or third party images, and lab environments shared by several people. For CVE-2026-59346, check whether guests use VMXNET3:
grep -l 'ethernet[0-9]*.virtualDev = "vmxnet3"' ~/vmware/*/*.vmx ~/Virtual\ Machines.localized/*/*.vmx 2>/dev/null
Adjust the paths to wherever your VMs live.
What to do now
- Upgrade VMware Workstation and Fusion to 26H1u1 on every host. Broadcom's advisory links the downloads and release notes for both.
- Push the update through device management if you have it, and ask teams to self-report hypervisor installs if you do not. Free desktop tools are easy to miss in an asset inventory.
- Disable shared folders on VMs that run untrusted code, and prefer a different virtual NIC type for analysis VMs until hosts are upgraded. The advisory lists no official workaround, so treat these as risk reduction, not a fix.
- Snapshot and rebuild analysis VMs after upgrading if they processed hostile samples while the host was vulnerable.
- Add desktop hypervisors to your patch SLA. They are host software with a direct line from guest to host, not developer convenience tools.
Why it matters
Developers use local VMs as a safety boundary: to try unfamiliar packages, run untrusted builds, test exploits or open suspicious files. That boundary only holds if the hypervisor holds. A guest-to-host escape turns "it ran in a VM" into "it ran on my laptop," which usually means access to SSH keys, cloud credentials and source code.
The disclosure timing is also worth noting. The advisory came out on 3 September, but the CVE records were not published until 7 October. If your tooling depends on CVE feeds, there was a month in which this fix existed and your dashboards were quiet. Following vendor advisories directly for the tools your engineers use daily closes that gap.
Try it yourself
Count the machines in your organization that run Workstation or Fusion, using the commands above or your endpoint management tool. Compare that number with what your asset inventory says. The difference is the part of your fleet that patches only when someone remembers.
Click through it at your own pace, or open it full screen.
Quick check
What does an attacker need to exploit VMSA-2026-0007?
Local administrative privileges inside a guest VM. For CVE-2026-59346 the VM also needs a VMXNET3 virtual network adapter. CVE-2026-59347 is in HGFS, which backs shared folders.
Which versions fix both CVEs?
VMware Workstation 26H1u1 and VMware Fusion 26H1u1. Versions 25H2 and 26H1 are affected.
Are there official workarounds?
No. Broadcom lists no workarounds for either CVE. Disabling shared folders or avoiding VMXNET3 on risky VMs reduces exposure, but upgrading is the fix.
