CVE-2026-51537

critical · 9.1

EIPStackGroup OpENer 2.3.0 (commit 76b95cf) has an out-of-bounds read issue in Connection Manager handling of ForwardOpen requests when processing short malformed packets. An attacker can send a valid ENIP outer frame carrying a malformed CIP ForwardOpen/LargeForwardOpen request, causing the parser to continue reading fields even when request data is insufficient. This issue is remotely triggerable via network traffic and does not require authentication.

9.1

CVSS

0.5%

EPSS (exploit prob.)

41st

EPSS percentile

2026-07-13

Published

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

Weaknesses

CWE-125

Affected products

Vendor	Product	Affected versions
opener_project	opener	2.3.0

Check a specific version with /api/v1/cve/match.

References

https://gist.github.com/MrAlaskan/a5fb0fb7765c9df80d28220ed558f04e
https://github.com/EIPStackGroup/OpENer/issues/564
https://github.com/EIPStackGroup/OpENer/issues/564

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-51537