CVEvulnerability

CVE-2026-40190

9.8 CRITICAL Published 2026-04-10 Modified 2026-10-26 Official page ↗
Status
Analyzed
Published
2026-04-10
Last modified
2026-10-26
Assigner
[email protected]
CVSS 3.1 ([email protected])
5.6 MEDIUM — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
CVSS 3.1 ([email protected])
9.8 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weaknesses
CWE-1321

Description

LangSmith Client SDKs provide SDK's for interacting with the LangSmith platform. Prior to 0.5.18, the LangSmith JavaScript/TypeScript SDK (langsmith) contains an incomplete prototype pollution fix in its internally vendored lodash set() utility. The baseAssignValue() function only guards against the __proto__ key, but fails to prevent traversal via constructor.prototype. This allows an attacker who controls keys in data processed by the createAnonymizer() API to pollute Object.prototype, affecting all objects in the Node.js process. This vulnerability is fixed in 0.5.18.

Affected configurations

• langchain langsmith (< 0.5.18)

Related

Weakness · CWE (1)

  • CWE-1321 Improperly Controlled Modification of Object Prototype Attributes weakness

References