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LangSmith SDK: Streaming token events bypass output redaction

Published Apr 23, 2026

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.

Affected products

Remediation

No remediation recorded yet.

Metrics

References (3)

Change history (0)

No recorded changes yet.

Sources
CVE.org / MITRE
Status PUBLISHED
Assigner GitHub_M
Published Apr 23, 2026
Updated Apr 23, 2026
Reserved Apr 17, 2026
CISA Vulnrichment
Updated Apr 23, 2026
NVD
Status Awaiting Analysis
Modified Jun 17, 2026
Red Hat
Severity n/a
Public date n/a
GHSA-RR7J-V2Q5-CHGV