{"cve":"CVE-2026-25528","nvd":{"published":"2026-02-09T21:15:48.857","modified":"2026-06-17T10:24:47.890","status":"Deferred","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N","score":5.8},"cwes":["CWE-918"],"references":["https://github.com/langchain-ai/langsmith-sdk/security/advisories/GHSA-v34v-rq6j-cj6p"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:22:27.261130201+00:00"},"epss":{"cve":"CVE-2026-25528","score":0.0032,"percentile":0.2505,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-v34v-rq6j-cj6p","url":"https://osv.dev/vulnerability/GHSA-v34v-rq6j-cj6p","summary":"LangSmith Client SDK Affected by Server-Side Request Forgery via Tracing Header Injection","modified":"2026-09-10T03:50:35.941728103Z","packages":[{"ecosystem":"PyPI","name":"langsmith","purl":"pkg:pypi/langsmith","ranges":[">=0.4.10 <0.6.3"],"fixed":["0.6.3"]},{"ecosystem":"npm","name":"langsmith","purl":"pkg:npm/langsmith","ranges":[">=0.3.41 <0.4.6"],"fixed":["0.4.6"]}]},{"id":"PYSEC-2026-2584","url":"https://osv.dev/vulnerability/PYSEC-2026-2584","summary":"LangSmith Client SDK Affected by Server-Side Request Forgery via Tracing Header Injection","modified":"2026-07-13T16:32:02.503615102Z","packages":[{"ecosystem":"PyPI","name":"langsmith","purl":"pkg:pypi/langsmith","ranges":[">=0.4.10 <0.6.3"],"fixed":["0.6.3"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}