Is CVE-2026-51537 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-51537 being exploited in the wild.

How severe is CVE-2026-51537?

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

Is there a fix for CVE-2026-51537?

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-2026-51537 attacked?

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

Am I affected by CVE-2026-51537?

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-2026-51537: EIPStackGroup OpENer out-of-bounds read in Connection Manager

CVE-2026-51537 · Severity: info · CVSS 7.5 · Published 2026-07-13

EIPStackGroup OpENer is an open-source implementation of the EtherNet/IP industrial protocol used to facilitate communication between industrial devices. A security vulnerability has been identified where a remote attacker can send a specially crafted network packet to crash the software. This results in a denial-of-service condition, potentially disrupting industrial operations and communication between connected equipment.

Technologies: EIPStackGroup OpENer. Vendors: EIPStackGroup.

Quick answers

Is CVE-2026-51537 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-51537 being exploited in the wild.
How severe is CVE-2026-51537?: 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-2026-51537?: 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-2026-51537 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-51537?: 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

An out-of-bounds read vulnerability exists in EIPStackGroup OpENer 2.3.0 (commit 76b95cf) within the Connection Manager's handling of ForwardOpen and LargeForwardOpen requests. The root cause is a 'parse-before-validate' logic error combined with missing boundary checks in low-level read helpers (e.g., GetByteFromMessage) located in cipconnectionmanager.c and cipconnectionobject.c. An unauthenticated remote attacker can establish a TCP connection to port 44818, register a session, and send a SendRRData packet with a malformed CIP request. If the request data is shorter than expected, the parser continues reading fields past the end of the stack-based receive buffer, leading to an AddressSanitizer-detected stack-buffer-overflow and process termination (Denial of Service).

Affected products

EIPStackGroup OpENer 2.3.0 (commit 76b95cf)

Timeline

2026-04-23: disclosed: Issue reported on GitHub by MrAlaskan
2026-07-09: advisory: Detailed security advisory published by researcher
2026-07-13: advisory: CVE-2026-51537 published in NVD

References

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