Out-of-bounds WriteWeakness · CWE-787

CVE-2025-41236

CRITICAL · 9.3 CVSS v3.1 Published 2025-07-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
98/100
Remediation priority · Urgent
No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
VMware ESXi, Workstation, and Fusion contain an integer-overflow vulnerability in the VMXNET3 virtual network adapter. A malicious actor with local administrative privileges on a virtual machine with VMXNET3 virtual network adapter may exploit this issue to execute code on the host. Non VMXNET3 virtual adapters are not affected by this issue.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A critical integer-overflow vulnerability exists in VMware's VMXNET3 virtual network adapter across ESXi, Workstation, and Fusion. An attacker with local administrative privileges on a virtual machine configured with the VMXNET3 adapter can exploit this flaw to escape the VM and execute arbitrary code on the host system.

MitigationApply VMware's official patches when released. Until then, consider migrating vulnerable VMs to alternative virtual network adapters (e.g., e1000e, vmxnet3 Enhanced) if operationally feasible, or restrict administrative access to VMs using VMXNET3.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify your VMware product type
    Determine whether the host runs ESXi, Workstation, or Fusion. On ESXi, use 'vmware -v' via SSH or check vSphere Client. On Workstation/Fusion, check Help > About.
    Affected if Product is ESXi, Workstation, or Fusion
  2. Check installed VMware version
    ESXi: 'vmware -v' or check host summary in vSphere Client. Workstation: Help > About VMware Workstation. Fusion: VMware Fusion > About VMware Fusion. Compare the version number to VMware's official affected version list.
    Affected if Version matches an affected release of ESXi, Workstation, or Fusion
  3. Enumerate VMs with VMXNET3 adapter
    ESXi: Use PowerCLI 'Get-VM | Get-NetworkAdapter | Where-Object {$_.Type -eq "Vmxnet3"}' or check VM settings in vSphere Client. Workstation/Fusion: Open VM settings, expand Network Adapter, verify adapter type.
    Affected if Any VM is configured to use VMXNET3 as the network adapter type
  4. Verify administrative VM access exists
    Review VM user permissions and local admin accounts within the guest VM. Check if untrusted users have administrative privileges on VMs using VMXNET3.
    Affected if Users with local administrative rights on a VMXNET3-equipped VM include non-host-admin accounts

Environment is affected if the VMware product version falls within the vulnerable range AND at least one VM uses the VMXNET3 adapter with accessible administrative privileges.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply VMware's official patches when released. Until then, consider migrating vulnerable VMs to alternative virtual network adapters (e.g., e1000e, vmxnet3 Enhanced) if operationally feasible, or restrict administrative access to VMs using VMXNET3.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,680
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-41236 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data