Out-of-bounds Read in Opener Project
CVE-2026-51537
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.
EPSS exploit prediction
EPSS: 0.006 (49.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.006 · change: +0.002
Affected products
- Opener Project — versions 2.3.0
Weakness classification (CWE)
References
- github.com/EIPStackGroup/OpENer/issues/564 (Exploit, Issue Tracking, Vendor Advisory)
- gist.github.com/MrAlaskan/a5fb0fb7765c9df80d28220ed558f04e (Third Party Advisory)
Frequently asked questions
- What is CVE-2026-51537?
- CVE-2026-51537 is a critical-severity vulnerability in Opener Project, classified under Out-of-bounds Read. CVSS score: 9.1/10. Published 2026-07-13.
- How severe is CVE-2026-51537?
- Critical severity. CVSS v3 base score is 9.1 out of 10.