Junglewise Threat Intelligence

CVE-2026-65423: o6 Automation open62541 integer overflow in UA_Variant arrayDimensions

CVE-2026-65423 · Severity: high · CVSS 8.8 · Published 2026-07-30

Executive brief

open62541 is an open-source implementation of OPC UA, a communication protocol used extensively in industrial automation and Internet of Things (IoT) environments. A vulnerability has been identified where the software incorrectly calculates memory requirements when processing complex data structures. An attacker could exploit this to gain unauthorized access to sensitive information, modify system data, or cause the software to crash, potentially disrupting industrial operations.

Technical details

An integer overflow vulnerability exists in open62541 within the UA_Variant arrayDimensions product computation. The flaw occurs when multiplying attacker-controlled arrayDimensions values into a size_t accumulator without sufficient overflow checks, causing the product to wrap and match a smaller-than-expected arrayLength. A remote attacker with low privileges can exploit this during Variant binary encoding or decoding to trigger an out-of-bounds write or read. This can lead to memory corruption, information disclosure, or a denial-of-service condition. Patches have been developed for versions 1.3, 1.4, 1.5, and the master branch.

Affected products

  • o6 Automation open62541 1.3.0 through 1.3.17, 1.4.0 through 1.4.16, 1.5.0 through 1.5.4, and master branch

Timeline

  • 2026-05-11: patched: Initial fix commits authored.
  • 2026-07-23: patched: Fixes merged into main branches.
  • 2026-07-30: disclosed: CVE published to NVD.

References