Quick answers
- Is CVE-2026-51540 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-51540 being exploited in the wild.
- How severe is CVE-2026-51540?
- Informational severity, with a CVSS score of 7.5, published 13 July 2026.
- Which products and versions are affected?
- EIPStackGroup OpENer 2.3.0 (up to commit 76b95cf).
- Is there a fix for CVE-2026-51540?
- 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-2026-51540 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-51540?
- 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 integer underflow vulnerability exists in OpENer 2.3.0 (up to commit 76b95cf) within the handling of connected explicit messages. The flaw occurs in the SendUnitData request processing where the length of a connected data item is decremented by 2 without sufficient validation. This underflow leads to an out-of-bounds read or stack buffer overflow during EPATH decoding in functions such as NotifyConnectedCommonPacketFormat and DecodePaddedEPath. A remote, unauthenticated attacker can trigger this by sending a malformed request to TCP port 44818, resulting in a process crash (DoS) or potential remote code execution.
Affected products
- EIPStackGroup OpENer 2.3.0 (up to commit 76b95cf)
Timeline
- 2026-05-13: disclosed: Issue reported on GitHub repository
- 2026-07-09: advisory: Detailed security advisory published by researcher
- 2026-07-13: advisory: CVE published to NVD dataset