Integer overflow in Open62541
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.
Vulnerability class: Integer Overflow
Published .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/open62541/open62541/commit/0cf4806768c493bc6ccffcd4419da24153b970ec (patch)
- github.com/open62541/open62541/pull/8298 (issue-tracking, patch)
- github.com/open62541/open62541/pull/8302 (issue-tracking, patch)
- github.com/open62541/open62541/blob/v1.5.6/src/ua_types_definition.c (technical-description)
- github.com/open62541/open62541/releases/tag/v1.5.7 (release-notes)
- www.vulncheck.com/advisories/open62541-1.5.0-before-1.5.7-integer-overflow-heap… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-116014?
- CVE-2026-116014 is a high-severity vulnerability in Open62541, classified under Integer Overflow or Wraparound. CVSS score: 8.1/10. Published 2026-10-24.
- How severe is CVE-2026-116014?
- High severity. CVSS v3 base score is 8.1 out of 10.