What’s Vulnerable › Vulnerabilities

CVE-2026-51538

• Severity: critical (CVSS 9.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-07-13 · updated 2026-08-11
• Weakness: CWE-284

Description

EIPStackGroup OpENer 2.3.0 (commit 76b95cf) suffers from an Incorrect Access Control vulnerability in its handling of encapsulation sessions. When the server processes critical encapsulation commands, it verifies whether the provided session_handle exists in the global session list, but it fails to verify whether that handle belongs to the specific TCP connection issuing the request. Because there is no strong binding between a session handle and its originating socket, any attacker on the network can use a valid session handle created by another legitimate client to bypass access controls.

Affected products

• EIPStackGroup OpENer EtherNet/IP: 2.3.0

References

• https://gist.github.com/MrAlaskan/8156ca3acd6754a9f66efede0a1351f2
• https://github.com/EIPStackGroup/OpENer/issues/565
• https://github.com/EIPStackGroup/OpENer/issues/565

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