MZ Automation libIEC61850

Summary

CISA has issued an advisory for multiple critical vulnerabilities in MZ Automation libIEC61850 (versions up to v1.6.1) that could allow unauthenticated network-adjacent attackers to crash IEC 61850 services or execute arbitrary code. The vulnerabilities stem from null pointer dereference (CWE-476) and carry CVSS scores of 7.5 (v3.1) and 8.7 (v4.0) in severity. MZ Automation recommends updating to the latest build, and CISA advises minimizing network exposure for control systems and implementing VPNs for remote access.

Full text

ICS Advisory MZ Automation libIEC61850 Release DateJuly 23, 2026 Alert CodeICSA-26-204-06 Related topics: Industrial Control System Vulnerabilities , Industrial Control Systems View CSAF Summary Successful exploitation of these vulnerabilities could allow an unauthenticated network-adjacent attacker to crash critical IEC 61850 services or execute arbitrary code, disrupting or compromising protection, visibility, and control functions. The following versions of MZ Automation libIEC61850 are affected: libIEC61850 >=v1.0.0|<=v1.6.1 CVSS Vendor Equipment Vulnerabilities v3 8.1 MZ Automation MZ Automation libIEC61850 Stack-based Buffer Overflow, Heap-based Buffer Overflow, Improper Handling of Syntactically Invalid Structure, NULL Pointer Dereference Background Critical Infrastructure Sectors: Critical Manufacturing, Energy, Transportation Systems Countries/Areas Deployed: Worldwide Company Headquarters Location: Germany Vulnerabilities Expand All + CVE-2026-50039 The affected product is vulnerable to a stack-based buffer overflow, which may allow an attacker to cause a memory corruption via a ReadRequest. View CVE Details Affected Products MZ Automation libIEC61850 Vendor:MZ Automation Product Version:MZ Automation libIEC61850: >=v1.0.0|<=v1.6.1 Product Status:known_affected Remediations Vendor fixMZ Automation recommends updating to the latest build of the libIEC61850 standard. Documentation can be found at https://github.com/mz-automation/libiec61850.https://github.com/mz-automation/libiec61850 Relevant CWE: CWE-121 Stack-based Buffer Overflow Metrics CVSS Version Base Score Base Severity Vector String 3.1 7.5 HIGH CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H 4.0 8.7 HIGH CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVE-2026-49035 The affected product is vulnerable to a heap-based buffer overflow via a crafted MMS Initiate request. Remote code execution (RCE) has been demonstrated when ASLR is disabled; memory corruption or denial of service may occur in configurations where ASLR is enabled. View CVE Details Affected Products MZ Automation libIEC61850 Vendor:MZ Automation Product Version:MZ Automation libIEC61850: >=v1.0.0|<=v1.6.1 Product Status:known_affected Remediations Vendor fixMZ Automation recommends updating to the latest build of the libIEC61850 standard. Documentation can be found at https://github.com/mz-automation/libiec61850.https://github.com/mz-automation/libiec61850 Relevant CWE: CWE-122 Heap-based Buffer Overflow Metrics CVSS Version Base Score Base Severity Vector String 3.1 8.1 HIGH CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H 4.0 9.2 CRITICAL CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N CVE-2026-50103 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. View CVE Details Affected Products MZ Automation libIEC61850 Vendor:MZ Automation Product Version:MZ Automation libIEC61850: >=v1.0.0|<=v1.6.1 Product Status:known_affected Remediations Vendor fixMZ Automation recommends updating to the latest build of the libIEC61850 standard. Documentation can be found at https://github.com/mz-automation/libiec61850.https://github.com/mz-automation/libiec61850 Relevant CWE: CWE-228 Improper Handling of Syntactically Invalid Structure Metrics CVSS Version Base Score Base Severity Vector String 3.1 6.5 MEDIUM CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H 4.0 7.1 HIGH CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVE-2026-50032 A NULL pointer dereference in the MMS Write Named Variable List handler, which may allow a network adjacent attacker to crash the server by sending a WriteRequest with an empty listOfData field. View CVE Details Affected Products MZ Automation libIEC61850 Vendor:MZ Automation Product Version:MZ Automation libIEC61850: >=v1.0.0|<=v1.6.1 Product Status:known_affected Remediations Vendor fixMZ Automation recommends updating to the latest build of the libIEC61850 standard. Documentation can be found at https://github.com/mz-automation/libiec61850.https://github.com/mz-automation/libiec61850 Relevant CWE: CWE-476 NULL Pointer Dereference Metrics CVSS Version Base Score Base Severity Vector String 3.1 7.5 HIGH CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H 4.0 8.7 HIGH CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N Acknowledgments Abhinav Agarwal reported these vulnerabilities to CISA Legal Notice and Terms of Use This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy). Recommended Practices CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities. Minimize network exposure for all control system devices and/or systems, ensuring they are not accessible from the internet. Locate control system networks and remote devices behind firewalls and isolating them from business networks. When remote access is required, use more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as the connected devices. CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures. CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov/ics. Several CISA products detailing cyber defense best practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies. CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies. Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents. CISA also recommends users take the following measures to protect themselves from social engineering attacks: Do not click web links or open attachments in unsolicited email messages. Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams. Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks. No known public exploitation specifically targeting these vulnerabilities has been reported to CISA at this time. Revision History Initial Release Date: 2026-07-23 Date Revision Summary 2026-07-23 1 Initial Publication Legal Notice and Terms of Use This product is provided subject to this Notification and this Privacy & Use policy. Vendor MZ Automation GmbH Tags Sector: Critical Manufacturing Sector, Energy Sector, Transportation Systems Sector Topics: Industrial Control System Vulnerabilities, Industrial Control Systems Please share your thoughts We recently updated our anonymous product survey; we welcome your feedback. Related Advisories Jul 23, 2026 ICS Advisory | ICSA-26-204-03 Weintek cMT3092X Jul 23, 2026 ICS Advisory | ICSA-26-204-01 Johnson Controls C-CURE 9000 and Victor application server Jul 23, 2026 ICS Advisory | ICSA-26-204-04 Panduit IntraVUE Jul 23, 2026 ICS Advisory | ICSA-26-204-07 MZ Automation lib60870

Entities