# CVE-2026-47876: VMXNET3 out-of-bounds write vulnerability

> A local admin in a VM with VMXNET3 can execute code on the host via an out-of-bounds write, requiring immediate patching.

- **Severity:** Critical 9.3 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 30 Jul 2026
- **Updated:** 30 Jul 2026
- **Also known as:** GHSA-8f48-75j5-mrf7

## What is CVE-2026-47876?

CVE-2026-47876 is a critical memory corruption vulnerability in VMware Cloud Foundation, published on 30 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-47876?


## How do I fix CVE-2026-47876?

No fix has been published for CVE-2026-47876 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-47876 being exploited?

There is no known exploitation of CVE-2026-47876 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-47876 and fix it if it is affected.

What it is: CVE-2026-47876 is a critical memory corruption vulnerability in VMware Cloud Foundation, published on 30 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-47876 in the wild and no public exploit code.

Affected product: VMware Cloud Foundation. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-47876/ (Markdown: https://insights.sbomify.com/CVE-2026-47876/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-47876
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-47876
- OSV: https://osv.dev/vulnerability/CVE-2026-47876

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-47876/
Summaries are generated and may contain mistakes; the official description above is the record.