CVE-2026-45134 — LangSmith Client SDK: Public prompt pull deserializes untrusted manifests without trust boundary warning

Description (CNA)

LangSmith Client SDKs provide SDK's for interacting with the LangSmith platform. Prior to LangSmith SDK Python 0.8.0 and JS/TS 0.6.0, the LangSmith SDK's prompt pull methods (pull_prompt / pull_prompt_commit in Python, pullPrompt / pullPromptCommit in JS/TS) fetch and deserialize prompt manifests from the LangSmith Hub. These manifests may contain serialized LangChain objects and model configuration that affect runtime behavior. When pulling a public prompt by owner/name identifier, the manifest content is controlled by an external party, but prior versions of the SDK did not distinguish this from pulling a prompt within the caller's own organization. This vulnerability is fixed in LangSmith SDK Python 0.8.0 and JS/TS 0.6.0.

Affected (CNA)

Vendor / product	Versions
langchain-ai / langsmith-sdk	affected < 0.8.0; affected < 0.6.0

CWE

CWE-502

References

https://github.com/langchain-ai/langsmith-sdk/security/advisories/GHSA-3644-q5cj-c5c7

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.