CVE-2026-41182: LangSmith SDK: Streaming token events bypass output redaction
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, hideoutputs in Python) do not apply to streaming token events. When an LLM run produces streaming output, each chunk is recorded as a newtoken event containing the raw token value. These events bypass the redaction pipeline entirely — prepareRunCreateOrUpdateInputs (JS) and hiderunoutputs (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 Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
LangSmith JavaScript SDKto a version that resolves this vulnerability.Fixed in 0.5.19 - Upgrade
Upgrade
LangSmith Python SDKto a version that resolves this vulnerability.Fixed in 0.7.31
Event History
Frequently Asked Questions
What is the severity of CVE-2026-41182?
CVE-2026-41182 has been classified as a high severity vulnerability due to its potential to bypass output redaction controls.
How do I fix CVE-2026-41182?
To fix CVE-2026-41182, upgrade to version 0.5.19 of the LangSmith JavaScript SDK or version 0.7.31 of the LangSmith Python SDK.
What are the main affected products in CVE-2026-41182?
CVE-2026-41182 affects the LangSmith JavaScript SDK versions earlier than 0.5.19 and the LangSmith Python SDK versions earlier than 0.7.31.
What is the impact of CVE-2026-41182 on data security?
CVE-2026-41182 can lead to unintended exposure of sensitive information due to improper output redaction in applications using the affected SDKs.
When was CVE-2026-41182 disclosed?
CVE-2026-41182 was disclosed as part of a security advisory by LangSmith and is currently available for remediation.