CVE-2026-51536

CRITICAL

OpENer 2.3.0 - Stack Buffer Overflow via CIP Packet Length Truncation and Signed Comparison Bypass

Title source: llm
STIX 2.1

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.

Scores

CVSS v3 9.1
EPSS 0.0047
EPSS Percentile 38.3%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact total

Details

CWE
CWE-190
Status published
Published Jul 13, 2026
Tracked Since Jul 14, 2026