Vulnerability · Published Jul 13, 2026 · Assigned by mitre
CVE-2026-51536
Critical 9.1
In plain English
A critical-severity integer overflow in the affected software. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 50% of all known vulnerabilities).
Official description
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.
Affected products (as reported)
Weakness: CWE-190 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H