Vulnerability record · CVE-2026-51537 · published 13 July 2026

CVE-2026-51537: Opener project opener out-of-bounds read vulnerability

Opener Project · Opener

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 3.1 Critical EPSS 0.65% · top 50.9% CWE-125 · Out-of-bounds read

9.1CVSS 3.1 base score

0.65%EPSS exploitation probability, 30 days

NoNot in CISA KEV

1Affected product versions listed by NVD

3References, 2 tagged exploit

11 Aug 2026Last modified by NVD

Description

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

Opener Opener Project

References

Link	Tags
https://gist.github.com/MrAlaskan/a5fb0fb7765c9df80d28220ed558f04e	Third Party Advisory
https://github.com/EIPStackGroup/OpENer/issues/564	ExploitIssue TrackingVendor Advisory
https://github.com/EIPStackGroup/OpENer/issues/564	ExploitIssue TrackingVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

10.0CVE-2021-21777Opener project opener out-of-bounds read vulnerabilityAn information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer 2.3 and development commit 8c73…EPSS 1.7%17 Jun 2021 9.8CVE-2026-51540Opener project opener vulnerabilityOpENer 2.3.0 (master branch up to commit 76b95cf) is vulnerable to a severe memory corruption issue caused by an integer underflow in the processing …EPSS 0.57%13 Jul 2026 9.8CVE-2022-43604Opener project opener out-of-bounds write vulnerabilityAn out-of-bounds write vulnerability exists in the GetAttributeList attribute_count_request functionality of EIP Stack Group OpENer development commi…EPSS 14%16 Mar 2023 9.8CVE-2022-43605Opener project opener out-of-bounds write vulnerabilityAn out-of-bounds write vulnerability exists in the SetAttributeList attribute_count_request functionality of EIP Stack Group OpENer development commi…EPSS 14%16 Mar 2023 9.8CVE-2020-13556Opener project opener out-of-bounds write vulnerabilityAn out-of-bounds write vulnerability exists in the Ethernet/IP server functionality of EIP Stack Group OpENer 2.3 and development commit 8c73bf3. A s…EPSS 4.7%11 Dec 2020 9.1CVE-2026-51536Opener project opener integer overflow vulnerabilityIn OpENer 2.3.0 (commit 76b95cf) when parsing incoming CIP (Common Industrial Protocol) network packets, the length parameter is inconsistently typed…EPSS 0.63%13 Jul 2026 9.1CVE-2026-51538Opener project opener improper access control vulnerabilityEIPStackGroup OpENer 2.3.0 (commit 76b95cf) suffers from an Incorrect Access Control vulnerability in its handling of encapsulation sessions. When th…EPSS 0.52%13 Jul 2026 9.1CVE-2026-51541Opener project opener out-of-bounds read vulnerabilityOpENer 2.3.0 (commit 76b95cf) has an out-of-bounds read issue in CIP message parsing when handling malformed explicit requests with a forged EPath si…EPSS 0.55%13 Jul 2026

Source: NIST National Vulnerability Database (record CVE-2026-51537), CISA KEV, FIRST EPSS (scores of 2026-09-29). This page is refreshed as NVD updates the record.