CVE-2026-67860 in open62541
Summary
by MITRE • 08/05/2026
open62541 1.5.5 contains a heap-based buffer overflow in the default HistoryRead path when the default history database is used with the memory backend.
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Analysis
by VulDB Data Team • 08/05/2026
The open62541 library version 1.5.5 contains a critical heap-based buffer overflow vulnerability within its default HistoryRead functionality when utilizing the memory backend for the default history database. This vulnerability stems from insufficient input validation and bounds checking during the processing of historical data reads, creating an exploitable condition that could allow remote attackers to execute arbitrary code or cause denial of service. The flaw specifically manifests when the system attempts to read historical data from the in-memory backend storage mechanism, which is the default configuration for many implementations.
The technical root cause of this vulnerability lies in improper memory management during the HistoryRead operation where the application fails to validate the size of incoming data structures before copying them into fixed-size buffers allocated on the heap. This classic buffer overflow condition occurs because the system does not properly verify that the requested historical data size matches the allocated buffer capacity, allowing an attacker to provide oversized data that overflows adjacent memory regions. The vulnerability is particularly concerning as it exists within the default configuration path, meaning that installations using the standard memory backend are inherently susceptible without any additional configuration changes.
The operational impact of this vulnerability extends across various industrial control systems and IoT environments that rely on open62541 for OPC UA communication protocols. Attackers could exploit this weakness to gain unauthorized access to systems, potentially leading to complete system compromise or disruption of critical operations in manufacturing, energy, and infrastructure management domains. The memory backend storage mechanism is commonly used in development environments and production systems where performance requirements favor in-memory storage over disk-based solutions, making this vulnerability particularly widespread.
Organizations should immediately implement mitigations including updating to the latest stable version of open62541 that contains the patched buffer overflow fix, implementing network segmentation to limit access to OPC UA endpoints, and deploying intrusion detection systems to monitor for suspicious HistoryRead requests. Additionally, security teams should conduct thorough code reviews of any custom implementations that interact with historical data functionality and consider implementing input validation layers to prevent oversized data from reaching the vulnerable code paths. This vulnerability aligns with CWE-121 heap-based buffer overflow patterns and represents a significant risk under ATT&CK technique T1059.007 for command and control operations through application layer protocols.
The fix for this vulnerability requires careful attention to proper bounds checking and memory allocation practices within the HistoryRead implementation, ensuring that all data transfers between the historical database backend and client applications are properly validated before any memory copying operations occur. System administrators should also consider implementing runtime protections such as address space layout randomization and stack canaries where possible, though these measures provide only partial protection against heap-based overflows. Regular security assessments of OPC UA implementations using open62541 are essential to identify similar vulnerabilities that may exist in custom extensions or third-party integrations.