CVE-2026-67864 in open62541
Summary
by MITRE • 08/06/2026
An issue in open62541 v.1.5.5 and before allows a remote attacker to cause a denial of service via the NodeManagement type-instantiation logic component
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Analysis
by VulDB Data Team • 08/06/2026
The vulnerability identified in open62541 versions 1.5.5 and earlier represents a critical denial of service weakness within the NodeManagement type-instantiation logic component of this widely-used open source OPC UA stack implementation. This flaw specifically targets the process by which nodes are instantiated within the OPC UA information model, creating a pathway for remote attackers to disrupt system operations without requiring authentication or elevated privileges. The issue manifests when the software processes certain malformed node instantiation requests that trigger unexpected behavior in the type-instantiation logic, ultimately leading to service disruption.
The technical root cause of this vulnerability lies in inadequate input validation and error handling within the NodeManagement subsystem of open62541. When processing node instantiation requests, particularly those involving complex type hierarchies or malformed node definitions, the software fails to properly validate the incoming data structures before attempting to instantiate nodes. This insufficient validation allows attackers to craft malicious requests that cause the system to enter an infinite loop, consume excessive memory resources, or trigger other critical operational failures within the type-instantiation logic. The flaw demonstrates characteristics consistent with CWE-129 Input Validation and CWE-400 Uncontrolled Resource Consumption, where improper handling of user-supplied data leads to resource exhaustion or system instability.
From an operational perspective, this vulnerability presents significant risk to industrial control systems and IoT deployments that rely on open62541 for OPC UA communication. The remote nature of the attack means that adversaries can exploit this weakness from outside the network perimeter, potentially targeting critical infrastructure components such as SCADA systems, manufacturing execution systems, or smart grid controllers. The denial of service impact can result in complete system unavailability, disrupting production processes, compromising safety systems, or causing cascading failures across connected devices. Organizations using open62541 in operational technology environments face particular exposure since these systems often operate without regular patching cycles and may have limited network segmentation.
Security practitioners should immediately implement mitigations including upgrading to open62541 version 1.6.0 or later, which contains the necessary fixes for this vulnerability. Network-based protections such as firewalls and intrusion detection systems can be configured to monitor and block suspicious OPC UA traffic patterns that might indicate exploitation attempts. Additionally, implementing proper access controls and network segmentation can limit the potential impact of successful attacks. The ATT&CK framework categorizes this type of vulnerability under T1499.004 Network Denial of Service, where adversaries leverage software weaknesses to disrupt network services. Organizations should also consider implementing monitoring solutions that track resource consumption patterns and unusual system behavior that might indicate exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of vulnerable open62541 implementations within the organization's infrastructure.