CVE-2026-51536
CriticalCVSS 9.1Exploitation Probability (EPSS)
Low risk38th percentile - higher than 38% of all known CVEs
Summary
In OpENer 2.3.0 (commit 76b95cf) when parsing CIP packets, the length parameter is inconsistently typed across the call stack. An int length is passed to a function expecting EipInt16, allowing crafted packets to cause overflow or negative values. This bypasses bounds checks and leads to a stack buffer overflow in DecodePaddedEPath.
Risk Assessment
An attacker can remotely crash or take control of industrial devices using OpENer, potentially halting production, damaging equipment, or compromising safety in operational environments.
Recommendation
Immediately update OpENer to a patched version or apply temporary firewall rules to block CIP traffic from untrusted sources.
Original NVD description (English source)
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.