GHSA-RR7J-V2Q5-CHGV: Streaming Token Redaction Bypass in LangSmith SDK

Vulnerability ID: GHSA-RR7J-V2Q5-CHGV
CVSS Score: 5.3
Published: 2026-04-16

The LangSmith SDK for both Python and JavaScript/TypeScript fails to apply output redaction controls to streaming token events. This oversight allows sensitive Large Language Model (LLM) outputs to bypass privacy configurations and transmit raw token data to the LangSmith backend, resulting in unintended data exposure.

TL;DR

A flaw in the LangSmith SDK's telemetry processing pipeline causes streaming token events to bypass hide_outputs redaction controls. Applications processing sensitive data via LLM streams transmit unredacted data to LangSmith servers despite active privacy settings.

Technical Details

Vulnerability ID: GHSA-RR7J-V2Q5-CHGV
CVSS Score: 5.3 (Medium)
Attack Vector: Network
CWE-ID: CWE-212
Exploit Status: None (No Public PoC)
KEV Status: Not Listed

Affected Systems

LangSmith SDK for Python
LangSmith SDK for JavaScript/TypeScript
langsmith (npm): < 0.5.19 (Fixed in: 0.5.19)
langsmith (PyPI): < 0.7.31 (Fixed in: 0.7.31)

Mitigation Strategies

Upgrade the LangSmith Python SDK via PyPI to a patched release.
Upgrade the LangSmith JavaScript/TypeScript SDK via npm to a patched release.
Disable streaming features on specific LLM chains that process high-sensitivity data if patching is delayed.
Audit existing LangSmith project logs and event traces for historical data leaks.

Remediation Steps:

Identify the current version of the LangSmith SDK using pip show langsmith or npm list langsmith.
Update the package.json or requirements.txt to specify langsmith >= 0.5.19 (JS) or langsmith >= 0.7.31 (Python).
Execute npm install or pip install --upgrade langsmith to apply the update.
Restart the application services to ensure the newly loaded SDK library handles subsequent traces.
Perform a test run with streaming enabled and verify the LangSmith events tab reflects redacted token entries.