Vulnerability · Published Oct 24, 2026 · Assigned by VulnCheck

CVE-2026-116014open62541 1.5.0 before 1.5.7 Integer Overflow Heap Buffer Overflow via Custom DataType

High 8.1

In plain English

A high-severity integer overflow in open62541 from open62541. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities).

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.4%top 62.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:13	open62541	no fix listed	DEBIAN-CVE-2026-116014
Debian:14	open62541	no fix listed	DEBIAN-CVE-2026-116014
Ubuntu:26.04:LTS	open62541	no fix listed	UBUNTU-CVE-2026-116014
Ubuntu:26.10	open62541	no fix listed	UBUNTU-CVE-2026-116014

Affected products (as reported)

Vendor	Product	Versions
open62541	open62541	1.5.0 – before 1.5.7

Weakness: CWE-190 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

https://github.com/open62541/open62541/commit/0cf4806768c493bc6ccffcd4419da24153b970ec patch
https://github.com/open62541/open62541/pull/8298 patch, issue-tracking
https://github.com/open62541/open62541/pull/8302 patch, issue-tracking
https://github.com/open62541/open62541/blob/v1.5.6/src/ua_types_definition.c#L274 technical-description
open62541 v1.5.7 Release Notes release-notes
VulnCheck Advisory: open62541 1.5.0 before 1.5.7 Integer Overflow Heap Buffer Overflow via Custom DataType third-party-advisory