CVE-2026-67869 in open62541
Summary
by MITRE • 08/06/2026
Buffer Overflow vulnerability in open62541 v1.5.5 allows a remote attacker to cause a denial of service via the Service_Call validates input arguments against runtime-resolved InputArguments metadata
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Analysis
by VulDB Data Team • 08/06/2026
The buffer overflow vulnerability in open62541 version 1.5.5 represents a critical security flaw that enables remote attackers to execute denial of service attacks through improper validation of input arguments during service calls. This vulnerability specifically manifests within the Service_Call function where the system fails to adequately validate input arguments against runtime-resolved InputArguments metadata, creating an exploitable condition that can be leveraged by malicious actors to disrupt service availability.
The technical implementation of this flaw occurs when the open62541 OPC UA stack processes service calls and attempts to validate incoming arguments. The system's failure to properly bounds-check input parameters against dynamically resolved metadata creates opportunities for attackers to supply malformed or oversized argument data that exceeds allocated buffer boundaries. This condition allows for memory corruption that can result in application crashes, process termination, or system instability. The vulnerability stems from inadequate input sanitization and validation mechanisms within the service call processing pipeline.
From an operational impact perspective, this vulnerability poses significant risks to industrial control systems and IoT deployments that rely on open62541 for OPC UA communication. Organizations using affected versions may experience unexpected service interruptions, system downtime, and potential data loss when attackers exploit this buffer overflow condition. The remote nature of the attack means that adversaries can target systems from external networks without requiring physical access or local privileges, making it particularly dangerous for operational technology environments where availability is critical.
The vulnerability aligns with CWE-121 which describes stack-based buffer overflow conditions, and represents a classic example of improper input validation that can lead to memory corruption. From an ATT&CK framework perspective, this weakness maps to techniques involving denial of service through resource exhaustion and system instability, potentially enabling further exploitation attempts. Organizations should prioritize immediate patching of affected systems to address this vulnerability.
Mitigation strategies include applying the latest available security patches from open62541 maintainers, implementing network segmentation to limit access to OPC UA services, deploying intrusion detection systems to monitor for suspicious service call patterns, and conducting regular security assessments of industrial control system environments. Additionally, organizations should consider implementing input validation controls at network boundaries and establishing robust monitoring procedures to detect potential exploitation attempts against vulnerable systems. The vulnerability demonstrates the importance of proper buffer management and input validation in industrial communication protocols where reliability and availability are paramount considerations.