CVE-2026-41182

LangSmith SDK: Streaming token events bypass output redaction

State
Published
Severity
5.3 Medium
Published
Apr 23, 2026
Updated
Apr 23, 2026
Reserved
Apr 17, 2026

Read the record on cve.org

Description

LangSmith Client SDKs provide SDK's for interacting with the LangSmith platform. Prior to version 0.5.19 of the JavaScript SDK and version 0.7.31 of the Python SDK, the LangSmith SDK's output redaction controls (hideOutputs in JS, hide_outputs in Python) do not apply to streaming token events. When an LLM run produces streaming output, each chunk is recorded as a new_token event containing the raw token value. These events bypass the redaction pipeline entirely — prepareRunCreateOrUpdateInputs (JS) and _hide_run_outputs (Python) only process the inputs and outputs fields on a run, never the events array. As a result, applications relying on output redaction to prevent sensitive LLM output from being stored in LangSmith will still leak the full streamed content via run events. Version 0.5.19 of the JavaScript SDK and version 0.7.31 of the Python SDK fix the issue.

Scores

CVSSScoreVectorSource
3.15.3 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NGitHub_M

Weaknesses

  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
  • CWE-359 Exposure of Private Personal Information to an Unauthorized Actor
  • CWE-532 Insertion of Sensitive Information into Log File

Affected Products

ProductVersions
langsmith-sdklangchain-ai
  • < 0.5.19Affected
  • < 0.7.31Affected

References

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