---
id: CVE-2026-116014
title: >-
  open62541 1.5.0 before 1.5.7 Integer Overflow Heap Buffer Overflow via Custom
  DataType
summary: >-
  open62541 1.5.0 before 1.5.7 contains an integer overflow in
  UA_DataType_fromStructureDescription() that wraps the 16-bit memSize field for
  large custom structure definitions. A malicious OPC UA server can supply
  DataType definitions via…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-190
vendor: open62541
product: open62541
affected:
  - open62541 >= 1.5.0 < 1.5.7
published: '2026-10-24'
updated: '2026-10-24'
sourceUpdated: '2026-10-24T11:40:32.200Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-116014'
references:
  - url: >-
      https://github.com/open62541/open62541/commit/0cf4806768c493bc6ccffcd4419da24153b970ec
  - url: 'https://github.com/open62541/open62541/pull/8298'
  - url: 'https://github.com/open62541/open62541/pull/8302'
  - url: >-
      https://github.com/open62541/open62541/blob/v1.5.6/src/ua_types_definition.c#L274
  - url: 'https://github.com/open62541/open62541/releases/tag/v1.5.7'
    label: open62541 v1.5.7 Release Notes
  - url: >-
      https://www.vulncheck.com/advisories/open62541-1.5.0-before-1.5.7-integer-overflow-heap-buffer-overflow-via-custom-datatype
    label: >-
      VulnCheck Advisory: open62541 1.5.0 before 1.5.7 Integer Overflow Heap
      Buffer Overflow via Custom DataType
tags:
  - cve.org
ingestedAt: '2026-10-24T11:57:47.029Z'
---

## Overview

open62541 1.5.0 before 1.5.7 contains an integer overflow in UA_DataType_fromStructureDescription() that wraps the 16-bit memSize field for large custom structure definitions. A malicious OPC UA server can supply DataType definitions via UA_Client_getRemoteDataTypes(), causing decodeBinaryStructure() to overflow the heap, crashing clients or enabling code execution.

## Affected

- `open62541 >= 1.5.0 < 1.5.7`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.