Review reviewCritical

CVE-2026-47876

VMware Cloud Foundation, vSphere Foundation, ESX

VMware ESX contains an out-of-bounds write 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.

CVSS
9.3
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.07.30
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 9.3

Vulnerability overview

VMware ESX contains an out-of-bounds write 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.

Affected product and versions

Product
VMware Cloud Foundation, vSphere Foundation, ESX
Affected versions
>= 9.1.x.x, >= 9.0.x.x, >= 5.x, >= 9.1.x.x < ESXi-9.1.0.0200-25557999, >= 9.0.x.x < ESXi-9.0.2.0100-25595025, >= 8.0 < ESXi80U3k-25595708, >= 5.1.x, >= 5.0.x
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that VMware Cloud Foundation, vSphere Foundation, ESX and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CWE
CWE-787