CVE-2026-40190
5.6 · MEDIUMOverview
CVE-2026-40190 is a medium-severity vulnerability affecting langchain langsmith. It was published on April 10, 2026 and has a CVSS 3.1 base score of 5.6 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 5.6, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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.
Remediation
Check the references section for vendor advisories and patches from langchain. Update langsmith to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| langchain | langsmith | >= 0, < 0.5.18 | Affected |
Frequently Asked Questions
What is CVE-2026-40190?
CVE-2026-40190 is a medium-severity vulnerability affecting langchain langsmith. It was published on April 10, 2026 and has a CVSS 3.1 base score of 5.6 (MEDIUM).
How severe is CVE-2026-40190?
This vulnerability has a CVSS 3.1 base score of 5.6, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-40190?
Check the references section for vendor advisories and patches from langchain. Update langsmith to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-40190?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-40190 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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