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 products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| langchain-ai | langsmith-sdk | < 0.5.18 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | python-langsmith | 0.10.3-1.1 | openSUSE-SU-2026:11284-1 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | langfuse-3 +1 | 3.164.0-r6 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| npm | langsmith | < 0.5.18 | 0.5.18 | GHSA-fw9q-39r9-c252 |
Advisories 2
- WID-SEC-2026-3046 IBM Concert: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 10, 2026
- openSUSE-SU-2026:11284-1 python313-langsmith-0.10.3-1.1 on GA media SUSE / openSUSE Security Updates · Jul 16, 2026