CVE-2026-50039: MZ Automation libIEC61850 stack-based buffer overflow via Read Request

CVE-2026-50039 · Severity: high · CVSS 7.5 · Published 2026-07-23

MZ Automation libIEC61850 is a software library used in industrial control systems for communication in the energy, manufacturing, and transportation sectors. A security flaw has been identified that allows an attacker to send a specially crafted data request over the network to crash the service. This could lead to a loss of visibility or control over critical infrastructure equipment, potentially disrupting operations.

Technologies: MZ Automation libIEC61850. Vendors: MZ Automation.

Quick answers

Is CVE-2026-50039 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-50039 being exploited in the wild.
How severe is CVE-2026-50039?
High severity, with a CVSS score of 7.5, published 23 July 2026.
Which products and versions are affected?
MZ Automation libIEC61850 v1.0.0 to v1.6.1.
Is there a fix for CVE-2026-50039?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-50039 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-50039?
Check whether you run MZ Automation libIEC61850 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A stack-based buffer overflow (CWE-121) exists in MZ Automation libIEC61850 versions 1.0.0 through 1.6.1. The vulnerability is triggered when the library processes a malformed MMS Read Request, leading to memory corruption. An unauthenticated remote attacker can exploit this over the network without user interaction to cause a denial-of-service (DoS) condition by crashing critical IEC 61850 services. While the primary impact is availability, such memory corruption vulnerabilities can sometimes be leveraged for broader system compromise depending on the environment. Users are advised to update to the latest build available on the vendor's GitHub repository.

Affected products

  • MZ Automation libIEC61850 v1.0.0 to v1.6.1

Timeline

  • 2026-07-23: disclosed: Initial publication of ICS Advisory ICSA-26-204-06
  • 2026-07-23: advisory: NVD published CVE-2026-50039 details

References

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