CVE-2026-45134

HIGH

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

Title source: cna
STIX 2.1

Description

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.

References (1)

Core 1
Core References

Scores

CVSS v3 7.1
EPSS 0.0020
EPSS Percentile 9.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-502
Status published
Products (6)
langchain-ai/langsmith-sdk < 0.6.0
langchain-ai/langsmith-sdk < 0.8.0
npm/langsmith 0 - 0.6.0npm
pypi/langchain 0 - 0.3.30PyPI
pypi/langchain-classic 0 - 1.0.7PyPI
pypi/langsmith 0 - 0.8.0PyPI
Published May 27, 2026
Tracked Since May 28, 2026