CVE-2026-51536

9.1 CRITICAL 0.6% exploit odds Fix listed Memory safety

What it is

In OpENer 2.3.0 (commit 76b95cf) when parsing incoming CIP (Common Industrial Protocol) network packets, the length parameter is inconsistently typed across the call stack. Specifically, an upstream length calculated as an int is passed to a downstream function that expects an EipInt16 (a 16-bit signed integer). If a maliciously crafted packet with specific length fields is processed, the length parameter can overflow or be truncated into a negative value. This negative length bypasses subsequent bounds checking (due to signed/unsigned comparison issues) and is ultimately used in memory operations, leading to a Stack Buffer Overflow when reading data in DecodePaddedEPath.

At a glance

Exploitability: Can be exploited over the network without logging in. High risk of data exposure, service disruption.
Exploit odds: 0.6% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-07-13 22:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-08-11 16:43 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.6% in the next 30 days (EPSS).
Severity: 9.1 CRITICAL (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-07-13 22:16 UTC
Last modified: 2026-08-11 16:43 UTC
Exploit probability: 0.6% · EPSS, next 30 days
Weakness: CWE-190 · Integer overflow
Record status: Analyzed

Affected

Opener Project Opener 2.3.0

Attack profile CVSS 3.1 · 9.1

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: High

Raw vector

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

Is it in your code?

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Fix and advisories

References

NVD record · CVE.org record