# CVE-2026-78012: Stack-based Buffer Overflow in Pyramid Solutions NetStaX EtherNet/IP Stack

> A stack-based buffer overflow in the NetStaX EtherNet/IP stack allows remote attackers to cause device crashes or potentially execute code via large Class 3 requests.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Sep 2026
- **Updated:** 4 Sep 2026
- **Also known as:** GHSA-xw8p-j9mr-grph

## What is CVE-2026-78012?

CVE-2026-78012 is a critical memory corruption vulnerability in Pyramid Solutions EtherNet/IP Adapter DLL Kit (EIPA), published on 1 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue in the NetStaX EtherNet/IP Stack prior to v5.6.1 could allow a large Class 3 explicit-message request to exceed the application-side receive buffer without generating an error or warning. The result could be memory corruption, a device crash, or a potential remote attack vector without the originating device receiving a CIP error indicating that the request could not be processed.

Weakness: CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2026-78012?


## How do I fix CVE-2026-78012?

No fix has been published for CVE-2026-78012 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-78012 being exploited?

There is no known exploitation of CVE-2026-78012 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-78012 and fix it if it is affected.

What it is: CVE-2026-78012 is a critical memory corruption vulnerability in Pyramid Solutions EtherNet/IP Adapter DLL Kit (EIPA), published on 1 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-78012 in the wild and no public exploit code.

Affected product: Pyramid Solutions EtherNet/IP Adapter DLL Kit (EIPA). 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-2026-78012/ (Markdown: https://insights.sbomify.com/CVE-2026-78012/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-78012
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-78012
- OSV: https://osv.dev/vulnerability/CVE-2026-78012

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-78012/
Summaries are generated and may contain mistakes; the official description above is the record.