What’s Vulnerable › Vulnerabilities

CVE-2026-51537

• Severity: critical (CVSS 9.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-07-13 · updated 2026-08-11
• Weakness: CWE-125

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.

Affected products

• EIPStackGroup OpENer EtherNet/IP: 2.3.0

References

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

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