CVE-2026-45134 PUBLISHED

LangSmith Client SDK: Public prompt pull deserializes untrusted manifests without trust boundary warning

Assigner: GitHub_M
Reserved: 08.05.2026 Published: 27.05.2026 Updated: 27.05.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N
CVSS Score: 7.1

Product Status

Vendor langchain-ai
Product langsmith-sdk
Versions
  • Version < 0.8.0 is affected
  • Version < 0.6.0 is affected

References

Problem Types

  • CWE-502: Deserialization of Untrusted Data CWE