CVE-2026-25528
Server-Side Request Forgery in LangSmith SDK Distributed Tracing
Publication date: 2026-02-09
Last updated on: 2026-02-09
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| langsmith | python_sdk | 0.6.3 |
| langsmith | javascript_sdk | 0.4.6 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-918 | The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
The LangSmith Client SDKs have a vulnerability in their distributed tracing feature that allows Server-Side Request Forgery (SSRF) through malicious HTTP headers.
Specifically, an attacker can inject arbitrary api_url values via the baggage header, which the SDK uses to configure replica endpoints.
Because the SDK accepts these attacker-controlled values without validation, it can be tricked into sending sensitive trace data to attacker-controlled endpoints when a traced operation completes.
This occurs during the parsing of incoming HTTP headers by RunTree.from_headers() in Python or RunTree.fromHeaders() in Typescript, and the vulnerable versions are fixed in Python SDK 0.6.3 and JavaScript SDK 0.4.6.
How can this vulnerability impact me? :
This vulnerability can lead to the exfiltration of sensitive trace data to attacker-controlled endpoints.
An attacker exploiting this flaw can inject malicious URLs that cause the SDK to send confidential information outside the trusted environment.
Such data leakage can compromise the confidentiality of your system's internal operations and potentially expose sensitive information.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, you should upgrade the LangSmith SDKs to the fixed versions.
- For the Python SDK, upgrade to version 0.6.3 or later.
- For the JavaScript SDK, upgrade to version 0.4.6 or later.