CVE-2026-50103 in libIEC61850
Summary
by MITRE • 07/24/2026
A NULL pointer dereference in the L2 GOOSE and R-GOOSE shared parser, which may allow a network-adjacent attacker to crash a subscribing application by sending a crafted GOOSE frame containing a malformed TLV value.
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Analysis
by VulDB Data Team • 07/24/2026
This vulnerability represents a critical null pointer dereference condition within the Layer 2 GOOSE and R-GOOSE protocol parsers used in industrial communication systems, particularly those implementing IEC 61850 standards for substation automation. The flaw occurs when the parser encounters a malformed Type-Length-Value structure within a GOOSE message, specifically when processing TLV elements that contain null or invalid pointer references during frame parsing operations. Such vulnerabilities are classified under CWE-476 as NULL Pointer Dereference, which represents a fundamental programming error where software attempts to access memory through a null pointer reference.
The attack vector requires an attacker to be network-adjacent to the target system, meaning they must be within the same broadcast domain or have direct network access to the substation communication infrastructure. This positioning allows the malicious actor to transmit specially crafted GOOSE frames that contain malformed TLV values designed to trigger the null pointer dereference condition. When a subscribing application processes this malformed frame, it attempts to dereference a null pointer during the parsing sequence, resulting in an application crash or segmentation fault that terminates the process.
The operational impact of this vulnerability extends beyond simple service disruption as it can compromise the integrity of critical substation automation systems that rely on GOOSE messaging for real-time control and monitoring operations. Substation protection systems, supervisory control and data acquisition systems, and other industrial control systems may experience unexpected termination of communication processes, potentially leading to loss of critical control information or delayed response times during fault conditions. This vulnerability particularly affects systems implementing IEC 61850 standards where GOOSE messages serve as the primary mechanism for fast transfer of critical control information between intelligent electronic devices.
Security considerations for this vulnerability align with ATT&CK technique T1499.001 for Network Denial of Service, where adversaries can disrupt system availability through crafted network traffic. The vulnerability also maps to CWE-121 as it involves improper handling of memory access patterns during parsing operations. Organizations should implement network segmentation and access controls to limit adjacent network access to critical systems. Application-level mitigations include input validation of TLV structures within GOOSE frames, implementation of robust error handling for malformed data, and regular security updates to parser implementations. Additionally, network monitoring solutions should be configured to detect anomalous GOOSE traffic patterns that may indicate exploitation attempts, while system administrators should ensure proper application hardening measures including stack canaries and address space layout randomization to mitigate potential exploitation scenarios.