Is CVE-2026-51536 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-51536 being exploited in the wild.

How severe is CVE-2026-51536?

Informational severity, with a CVSS score of 7.5, published 13 July 2026.

Which products and versions are affected?

EIPStackGroup OpENer 2.3.0 (commit 76b95cf).

Is there a fix for CVE-2026-51536?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-51536 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-51536?

Check whether you run EIPStackGroup OpENer at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-51536: EIPStackGroup OpENer stack buffer overflow in CIP message router

CVE-2026-51536 · Severity: info · CVSS 7.5 · Published 2026-07-13

OpENer is an open-source implementation of the EtherNet/IP protocol used in industrial automation and control systems. A vulnerability in how the software handles network messages could allow a remote attacker to crash the service by sending a specially crafted packet. This results in a denial-of-service condition, potentially disrupting industrial operations and communication between devices on the factory floor.

Technologies: EIPStackGroup OpENer. Vendors: EIPStackGroup.

Quick answers

Is CVE-2026-51536 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-51536 being exploited in the wild.
How severe is CVE-2026-51536?: Informational severity, with a CVSS score of 7.5, published 13 July 2026.
Which products and versions are affected?: EIPStackGroup OpENer 2.3.0 (commit 76b95cf).
Is there a fix for CVE-2026-51536?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-51536 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-51536?: Check whether you run EIPStackGroup OpENer at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A stack-based buffer overflow exists in OpENer 2.3.0 (commit 76b95cf) within the CIP message router and EPATH decoding logic. The vulnerability is caused by inconsistent integer typing where a 32-bit 'int' length is passed to functions expecting a 16-bit signed 'EipInt16', leading to truncation and negative values. These negative values bypass unsigned bounds checks (CWE-194) and result in an underflow when calculating remaining data size. A remote, unauthenticated attacker can trigger this by sending a crafted SendUnitData request over TCP port 44818, leading to a crash in DecodePaddedEPath.

Affected products

EIPStackGroup OpENer 2.3.0 (commit 76b95cf)

Timeline

2026-04-23: disclosed: Issue reported on GitHub by MrAlaskan
2026-07-13: advisory: NVD published CVE-2026-51536

References

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