CVE-2026-69200 json
node-opcua: Prototype Pollution via internal `fieldsToJson()` implementation (Related to CVE-2024-57086)
published 4mo ago modified last mo. also EUVD-2026-80867 , GHSA-cv5q-7543-48q4
Unreviewed: the maintainers' own advisory
Published by the maintainers on their GitHub repository node-opcua/node-opcua. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.
- cvss
- 3.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 28%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- npm node-opcua-client 2.145.0
- node-opcua_project node-opcua 2.145.0
Is CVE-2026-69200 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- last mo.
Exploit prediction
0.35% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-11).
Exploits and checks
- github.com https://github.com/node-opcua/node-opcua/security/advisories/GHSA-cv5q-7543-48q4 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | node-opcua-client | 2.144.0, 2.138.1, 2.138.0 |
2.145.0 |
Affected products
- node-opcua node-opcua
Classification
- Weakness
-
- CWE-1321 Improperly Controlled Modification of Object Prototype Attributes
References
Sources
- CVE List CVE-2026-69200
- NVD CVE-2026-69200
- Maintainer advisory GHSA-cv5q-7543-48q4
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
The maintainers of node-opcua/node-opcua published their own advisory on GitHub. Reviewed sources take precedence over it.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.