CVE-2026-51537

Critical

Description

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.

SeverityCritical
CVSS9.1
Exploit probability—
ProductOpener
PublishedJul 13, 2026
First seenJul 13, 2026

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
opener_project opener2.3.0—

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CVE-2026-51537 · Opener · Dark Radar