CVE-2026-25528

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.
Configurations

No configuration.

History

09 Feb 2026, 21:15

Type Values Removed Values Added
New CVE

Information

Published : 2026-02-09 21:15

Updated : 2026-02-09 21:55


NVD link : CVE-2026-25528

Mitre link : CVE-2026-25528

CVE.ORG link : CVE-2026-25528


JSON object : View

Products Affected

No product.

CWE
CWE-918

Server-Side Request Forgery (SSRF)