{"id":"CVE-2026-40190","revision":"5ecb6d9f9bf2464b8e7c8777b59d61bb","records":[{"revision":"5ecb6d9f9bf2464b8e7c8777b59d61bb","observedAt":"2026-10-27T10:09:56.341+00:00","statement":{"source":"nvd","id":"CVE-2026-40190","aliases":[],"title":"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() uti…","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.","state":0,"publishedAt":"2026-04-10T20:16:24.043+00:00","modifiedAt":"2026-10-26T21:10:00.17+00:00","affected":[],"metrics":[{"system":"CVSS 3.1 · security-advisories@github.com · Secondary","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L","score":5.6,"severity":"MEDIUM"},{"system":"CVSS 3.1 · nvd@nist.gov · Primary","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8,"severity":"CRITICAL"}],"references":["https://github.com/langchain-ai/langsmith-sdk/security/advisories/GHSA-fw9q-39r9-c252"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-40190","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Analyzed","weaknesses":["CWE-1321"],"productCriteria":["cpe:2.3:a:langchain:langsmith:*:*:*:*:*:node.js:*:*"],"sourceDates":{"published":"2026-04-10T20:16:24.043","lastModified":"2026-10-26T21:10:00.170"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-40190","identifiers":["CVE-2026-40190"]},"retained":false,"historicalAffected":[]}],"coverage":[]}