CVE-2026-59152
MediumCVSS 5.0Exploitation Probability (EPSS)
Low risk7th percentile - higher than 7% of all known CVEs
Summary
A vulnerability in LangSmith Client SDKs prior to version 0.8.18 allows an attacker to send an HTTP request to a server running TracingMiddleware, causing it to read an arbitrary file from the local filesystem and upload it as a trace attachment to LangSmith. Depending on the distributed trace system deployment, triggering the read may not require authentication.
Risk Assessment
The risk is a trust-boundary crossing: a party with workspace trace-read access (e.g., low-privilege member, contractor, or compromised teammate account) can read files from any server running TracingMiddleware, a capability outside that workspace's intended trust boundary.
Recommendation
Immediately upgrade LangSmith Client SDK to version 0.8.18 or later, which contains the fix for this vulnerability.
Original NVD description (English source)
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.