Summary
LangSmith SDK: Streaming token events bypass output redaction
Full technical description
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.
Details
Both JS and Python SDKs are affected. The same pattern exists in both:
- JS SDK:
traceable.ts:997-1003andtraceable.ts:1044-1050 - Python SDK:
run_helpers.py:1924andrun_helpers.py:1996
In both SDKs, new_token events with raw kwargs.token values are added during streaming, and the redaction pipeline (hideOutputs in JS, hide_outputs in Python) only processes inputs/outputs, never events.
Impact
CVE-2026-41182 has a CVSS score of 5.3 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.5.19, 0.7.31); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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See it in your environmentNew to Kodem? Get a demo →Remediation advice
langsmith to 0.5.19 or later; langsmith to 0.7.31 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-41182? CVE-2026-41182 is a medium-severity security vulnerability in langsmith (npm), affecting versions <= 0.5.18. It is fixed in 0.5.19, 0.7.31.
- How severe is CVE-2026-41182? CVE-2026-41182 has a CVSS score of 5.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of langsmith are affected by CVE-2026-41182? langsmith (npm) versions <= 0.5.18 is affected.
- Is there a fix for CVE-2026-41182? Yes. CVE-2026-41182 is fixed in 0.5.19, 0.7.31. Upgrade to this version or later.
- Is CVE-2026-41182 exploitable, and should I be worried? Whether CVE-2026-41182 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-41182 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-41182?
- Upgrade
langsmithto 0.5.19 or later - Upgrade
langsmithto 0.7.31 or later
- Upgrade