What is CVE-2026-69200?

CVE-2026-69200 is a low-severity vulnerability in Node-Opcua, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 3.7/10. Published 2026-09-16.

How severe is CVE-2026-69200?

Low severity. CVSS v3 base score is 3.7 out of 10.

Prototype Pollution in Node-Opcua

CVE-2026-69200

node-opcua is an OPC UA implementation for TypeScript and Node.js. Prior to node-opcua-client 2.145.0, the internal fieldsToJson method in packages/node-opcua-client/source/alarms_and_conditions/client_alarm.ts directly assigns unsanitized field names and allows a __proto__.pollutedKey path to modify Object.prototype. Successful exploitation requires an application to expose attacker-controlled event fields to fieldsToJson and may cause denial of service or application logic corruption. This vulnerability is fixed in 2.145.0.

Vulnerability class: Prototype Pollution

CVSS v3 metric

CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L.

Affected products

Node-opcua — versions < 2.145.0

Weakness classification (CWE)

CWE-1321 — Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution)

References

security-advisories@github.com (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-69200?: CVE-2026-69200 is a low-severity vulnerability in Node-Opcua, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 3.7/10. Published 2026-09-16.
How severe is CVE-2026-69200?: Low severity. CVSS v3 base score is 3.7 out of 10.