What’s Vulnerable › Vulnerabilities

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

• Severity: high (CVSS 8.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-24 · updated 2026-10-29
• Weakness: CWE-190

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 products

• open62541: from 1.5.0 before 1.5.7 — fixed in 1.5.7

How to fix

Upgrade to a fixed version: open62541 1.5.7. Check the vendor advisory for mitigations.

References

• https://github.com/open62541/open62541/blob/v1.5.6/src/ua_types_definition.c#L274
• https://github.com/open62541/open62541/commit/0cf4806768c493bc6ccffcd4419da24153b970ec
• https://github.com/open62541/open62541/pull/8298
• https://github.com/open62541/open62541/pull/8302
• https://github.com/open62541/open62541/releases/tag/v1.5.7
• https://www.vulncheck.com/advisories/open62541-1.5.0-before-1.5.7-integer-overflow-heap-buffer-overflow-via-custom-datatype

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