CVE-2026-116014

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.

CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

• 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