CVE-2026-45134 HIGH

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

Vendor Langchain-Ai
Product langsmith-sdk
Weakness CWE-502 · Unsafe deserialization
Published May 27, 2026
Last update June 2, 2026
View on NVD All CVEs

CVSS base score

7.1/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction Required
Confidentiality High
Integrity Low

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

May 27, 2026 CVE published
June 2, 2026 Record updated