# CVE-2026-51537: Memory corruption in n/a

> Remote attackers can trigger out-of-bounds reads in OpENer via malformed CIP ForwardOpen requests, potentially causing crashes or data exposure.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 13 Jul 2026
- **Updated:** 14 Jul 2026
- **Also known as:** GHSA-7wpf-vhm2-3mpw

## What is CVE-2026-51537?

CVE-2026-51537 is a critical memory corruption vulnerability in n/a, published on 13 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

EIPStackGroup OpENer 2.3.0 (commit 76b95cf) has an out-of-bounds read issue in Connection Manager handling of ForwardOpen requests when processing short malformed packets. An attacker can send a valid ENIP outer frame carrying a malformed CIP ForwardOpen/LargeForwardOpen request, causing the parser to continue reading fields even when request data is insufficient. This issue is remotely triggerable via network traffic and does not require authentication.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-51537?

It affects 1 product.


Products: Opener Project Opener.

## How do I fix CVE-2026-51537?

No fix has been published for CVE-2026-51537 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-51537 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-51537 exists.

## Other vulnerabilities in n/a

- [CVE-2022-43604](https://insights.sbomify.com/CVE-2022-43604/): Memory corruption in OpENer (critical 10.0)
- [CVE-2022-43605](https://insights.sbomify.com/CVE-2022-43605/): Memory corruption in OpENer (critical 10.0)
- [CVE-2026-51540](https://insights.sbomify.com/CVE-2026-51540/): Integer overflow in n/a (critical 9.8)
- [CVE-2020-13556](https://insights.sbomify.com/CVE-2020-13556/): Memory corruption in EIP Stack Group (critical 9.8)
- [CVE-2026-51536](https://insights.sbomify.com/CVE-2026-51536/): Integer overflow in n/a (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-51537 and fix it if it is affected.

What it is: CVE-2026-51537 is a critical memory corruption vulnerability in n/a, published on 13 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-51537 exists.

Affected product: n/a. 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-2026-51537/ (Markdown: https://insights.sbomify.com/CVE-2026-51537/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-51537
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-51537
- OSV: https://osv.dev/vulnerability/CVE-2026-51537

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-51537/
Summaries are generated and may contain mistakes; the official description above is the record.