langchain-ai LangSmith SDK up to 0.8.17 TracingMiddleware unrestricted upload

Summaryinfo

A vulnerability has been found in langchain-ai LangSmith SDK up to 0.8.17 and classified as critical. This affects an unknown part of the component TracingMiddleware. This manipulation causes unrestricted upload. This vulnerability is tracked as CVE-2026-59152. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability was found in langchain-ai LangSmith SDK up to 0.8.17. It has been declared as critical. Affected by this vulnerability is an unknown part of the component TracingMiddleware. The manipulation with an unknown input leads to a unrestricted upload vulnerability. The CWE definition for the vulnerability is CWE-434. The product allows the attacker to upload or transfer files of dangerous types that can be automatically processed within the product's environment. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-59152 since 07/02/2026. The exploitation appears to be easy. The attack can be launched remotely. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1608.002 for this issue.

Upgrading to version 0.8.18 eliminates this vulnerability.

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Productinfo

Type

• Artificial Intelligence Software

Vendor

• langchain-ai

Name

• LangSmith SDK

Version

• 0.8.0
• 0.8.1
• 0.8.2
• 0.8.3
• 0.8.4
• 0.8.5
• 0.8.6
• 0.8.7
• 0.8.8
• 0.8.9
• 0.8.10
• 0.8.11
• 0.8.12
• 0.8.13
• 0.8.14
• 0.8.15
• 0.8.16
• 0.8.17

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

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• 🔒
• 🔒

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