Vulnerability · Published Jul 6, 2026 · Assigned by GitHub_M

CVE-2026-59152Arbitrary server-side file read in LangSmith SDK TracingMiddleware

Medium 5.0

In plain English

A medium-severity path traversal in langsmith-sdk from langchain-ai. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.0Medium
Exploit odds (30 days)0.2%top 90.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

LangSmith Client SDKs provide SDK's for interacting with the LangSmith platform. Prior to 0.8.18, an attacker who can send an HTTP request to a server running the LangSmith SDK's TracingMiddleware can cause that server to read an arbitrary file from its local filesystem and upload the contents to LangSmith as a trace attachment. Depending on how the distributed trace system is deployed, triggering a read may not require authentication. Retrieving the contents requires read access to the LangSmith workspace the traces are sent to. The net effect is a trust-boundary crossing: a party with workspace trace-read access (for example a low-privilege workspace member, a contractor, or a compromised teammate account) gains the ability to read files from any server running TracingMiddleware, a capability outside that workspace's intended trust boundary. This vulnerability is fixed in 0.8.18.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
PyPIlangsmith0.8.18GHSA-f4xh-w4cj-qxq8

Affected products (as reported)

VendorProductVersions
langchain-ai langsmith-sdk < 0.8.18

Weakness: CWE-22, CWE-346, CWE-843 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N

References