CVE-2026-51541

OpENer 2.3.0 (commit 76b95cf) has an out-of-bounds read issue in CIP message parsing when handling malformed explicit requests with a forged EPath size. An attacker can send a valid ENIP SendRRData frame carrying a very short CIP payload whose path_size field claims that many more path words are present than are actually available. Because the parser trusts the attacker-controlled path_size and continues decoding path segments without a remaining-length boundary, it reads beyond the end of the stack receive buffer.

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

• https://gist.github.com/MrAlaskan/705c680856e48c535148265c0899ad4b
• https://github.com/EIPStackGroup/OpENer/issues/582
• https://github.com/EIPStackGroup/OpENer/issues/582