Medium severity5.6NVD Advisory· Published Apr 10, 2026· Updated May 29, 2026
CVE-2026-40190
CVE-2026-40190
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.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
langsmithnpm | < 0.5.18 | 0.5.18 |
Affected products
23- osv-coords23 versionspkg:apk/chainguard/kibana-8.17pkg:apk/chainguard/kibana-8.17-bitnamipkg:apk/chainguard/kibana-8.17-iamguardedpkg:apk/chainguard/kibana-8.19pkg:apk/chainguard/kibana-8.19-bitnamipkg:apk/chainguard/kibana-8.19-iamguardedpkg:apk/chainguard/kibana-9.0pkg:apk/chainguard/kibana-9.0-bitnamipkg:apk/chainguard/kibana-9.0-iamguardedpkg:apk/chainguard/kibana-9.1pkg:apk/chainguard/kibana-9.1-iamguardedpkg:apk/chainguard/kibana-9.2pkg:apk/chainguard/kibana-9.2-iamguardedpkg:apk/chainguard/kibana-9.3pkg:apk/chainguard/kibana-9.3-iamguardedpkg:apk/chainguard/langfuse-2-workerpkg:apk/chainguard/langfuse-3-workerpkg:apk/chainguard/langfuse-fips-2-workerpkg:apk/chainguard/langfuse-fips-3pkg:apk/chainguard/langfuse-fips-3-workerpkg:apk/chainguard/librechatpkg:apk/wolfi/langfuse-3-workerpkg:npm/langsmith
< 8.17.10-r17+ 22 more
- (no CPE)range: < 8.17.10-r17
- (no CPE)range: < 8.17.10-r17
- (no CPE)range: < 8.17.10-r17
- (no CPE)range: < 8.19.14-r2
- (no CPE)range: < 8.19.14-r2
- (no CPE)range: < 8.19.14-r2
- (no CPE)range: < 9.0.8-r19
- (no CPE)range: < 9.0.8-r19
- (no CPE)range: < 9.0.8-r19
- (no CPE)range: < 9.1.10-r12
- (no CPE)range: < 9.1.10-r12
- (no CPE)range: < 9.2.7-r5
- (no CPE)range: < 9.2.7-r5
- (no CPE)range: < 9.3.3-r4
- (no CPE)range: < 9.3.3-r4
- (no CPE)range: < 2.95.12-r19
- (no CPE)range: < 3.164.0-r6
- (no CPE)range: < 2.95.12-r22
- (no CPE)range: < 3.164.0-r3
- (no CPE)range: < 3.164.0-r3
- (no CPE)range: < 0.8.4-r5
- (no CPE)range: < 3.164.0-r6
- (no CPE)range: < 0.5.18
Patches
Vulnerability mechanics
References
5- github.com/advisories/GHSA-fw9q-39r9-c252ghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2026-40190ghsaADVISORY
- github.com/langchain-ai/langsmith-sdk/commit/31d3c3aec02892f4312baae112f817d6b2f0ebe3ghsaWEB
- github.com/langchain-ai/langsmith-sdk/pull/2690ghsaWEB
- github.com/langchain-ai/langsmith-sdk/security/advisories/GHSA-fw9q-39r9-c252nvdWEB
News mentions
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