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CVE-2026-25528GHSA-V34V-RQ6J-CJ6PPYSEC-2026-2584

LangSmith Client SDK Affected by Server-Side Request Forgery via Tracing Header Injection

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 0.6.3, 0.4.6
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: yes
  • Technical impact: partial

Summary

LangSmith Client SDKs provide SDK's for interacting with the LangSmith platform. The LangSmith SDK's distributed tracing feature is vulnerable to Server-Side Request Forgery via malicious HTTP headers. An attacker can inject arbitrary api_url values through the baggage header, causing the SDK to exfiltrate sensitive trace data to attacker-controlled endpoints. When using distributed tracing, the SDK parses incoming HTTP headers via RunTree.from_headers() in Python or RunTree.fromHeaders() in Typescript. The baggage header can contain replica configurations including api_url and api_key fields. Prior to the fix, these attacker-controlled values were accepted without validation. When a traced operation completes, the SDK's post() and patch() methods send run data to all configured replica URLs, including any injected by an attacker. This vulnerability is fixed in version 0.6.3 of the Python SDK and 0.4.6 of the JavaScript SDK.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: yes · Technical impact: partial

  3. Record last updated

Affected versions

  • langchain-ai langsmith-sdk

    From 0.4.10 · fixed in 0.6.3

  • langsmithPyPI

    From 0.4.10 · fixed in 0.6.3

  • langsmithnpm

    From 0.3.41 · fixed in 0.4.6

References 1

GitHub · langchain-ai/langsmith-sdk