The vulnerability is an out-of-bounds read in the server‑side parser for EtherNet/IP ForwardOpen connection‑path data. This flaw can be triggered remotely by sending specially crafted packets to the OpENer host, resulting in an uncontrolled read that leads to a service interruption of the OpENer server. The exploit causes a denial of service but does not provide code execution or privilege escalation.

OpENer v2.3, specifically the code included in commit 76b95cf, is affected. Any installation of this version that processes EtherNet/IP ForwardOpen requests is potentially vulnerable.

With a CVSS score of 7.5, this vulnerability is rated High. The EPSS score is reported as less than 1% and it is not listed in CISA's KEV catalog, indicating that no known public exploits exist yet. The severity of the issue is high because a successful exploit will stop the OpENer service and disrupt any communications relying on it. The likelihood of exploitation is uncertain but could be significant in environments where OpENer is exposed to untrusted networks.