The vulnerability in JoeCastrom mcp-chat-studio (up to version 1.5.0) allows an attacker to perform server-side request forgery via manipulation of the req.query.base_url argument in the LLM Models API's server/routes/llm.js file. This enables remote attackers to induce the server to make arbitrary HTTP requests. The vulnerability has a CVSS 4.0 base score of 6.9 (medium severity) with network attack vector, low complexity, no privileges or user interaction required, and partial impact on confidentiality, integrity, and availability. The project has been informed but has not issued a patch or official remediation guidance.

Successful exploitation of this SSRF vulnerability could allow an attacker to make the vulnerable server perform arbitrary HTTP requests, potentially accessing internal resources or services not otherwise reachable. This may lead to partial confidentiality, integrity, and availability impacts as indicated by the CVSS vector. However, no active exploitation in the wild has been confirmed.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since the project has not responded or released a fix, users should consider implementing network-level controls to restrict outbound requests from the affected server or apply input validation and sanitization on the req.query.base_url parameter as temporary mitigations until an official fix is available.