CVE-2026-19206 in libiec61850
Summary
by MITRE • 08/07/2026
A security flaw has been discovered in MZ Automation libiec61850 up to 1.6.1. This affects the function SVReceiver_stopThreadless of the file src/sampled_values/sv_subscriber.c of the component ASDU Element Handler. Performing a manipulation results in heap-based buffer overflow. The attack must be initiated from a local position. The exploit has been released to the public and may be used for attacks. Upgrading to version 1.6.2 is able to mitigate this issue. The patch is named a96bd674e0238276dd1387d31d52e55229d0771e. The affected component should be upgraded.
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Analysis
by VulDB Data Team • 08/07/2026
The vulnerability in MZ Automation libiec61850 version 1.6.1 and earlier represents a critical heap-based buffer overflow condition that resides within the ASDU Element Handler component. This flaw specifically manifests in the SVReceiver_stopThreadless function located in the src/sampled_values/sv_subscriber.c file, where improper input validation allows malicious actors to manipulate memory allocation patterns. The vulnerability's classification as a heap-based buffer overflow aligns with CWE-121, which describes conditions where data written to heap memory exceeds allocated boundaries. The attack vector requires local system access, making this a privilege escalation vulnerability that could be exploited by users with physical or network access to the affected system. This presents significant operational risk in industrial control systems where such libraries are commonly deployed for communication protocols.
The technical exploitation of this vulnerability occurs through manipulation of the SVReceiver_stopThreadless function which handles sampled values subscriber operations in accordance with IEC 61850 standards. The buffer overflow condition arises when the application fails to properly validate input parameters before writing data to heap-allocated memory regions. Attackers can craft specific inputs that cause memory corruption, potentially leading to arbitrary code execution or denial of service conditions. The vulnerability's impact is particularly concerning given that IEC 61850 protocols are fundamental to power grid automation systems and other critical infrastructure environments where reliability and security are paramount.
From an operational perspective, this vulnerability exposes systems to potential compromise through local exploitation, which could be leveraged by malicious insiders or attackers who have gained system access. The availability of public exploits increases the likelihood of successful attacks, making it essential for organizations to implement immediate remediation measures. The vulnerability's presence in the ASDU Element Handler component suggests broader impacts across IEC 61850 communication stacks where similar patterns may exist. Organizations utilizing this library in industrial environments must prioritize patch deployment as part of their cybersecurity posture, particularly given the critical nature of the affected systems.
Mitigation strategies should focus on immediate upgrade to version 1.6.2 which incorporates the patch identified by commit hash a96bd674e0238276dd1387d31d52e55229d0771e. This update addresses the buffer overflow condition through proper input validation and memory management practices that prevent heap corruption. Additionally, organizations should implement network segmentation and access controls to limit local system access points, reducing potential attack surfaces. The remediation process should include comprehensive testing of patched systems to ensure compatibility with existing IEC 61850 implementations. Security monitoring should be enhanced to detect anomalous behavior patterns that might indicate exploitation attempts, particularly in environments where these libraries are deployed for critical infrastructure operations.