CVE-2026-34163 HIGH

CVE-2026-34163: Server-Side Request Forgery via MCP Tools Endpoint in FastGPT

Vendor Labring
Product FastGPT
Weakness CWE-918 · SSRF
Published March 31, 2026
Last update March 31, 2026

CVSS base score

7.7/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality High
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

What the vulnerability does

01Description

FastGPT is an AI Agent building platform. Prior to version 4.14.9.5, FastGPT's MCP (Model Context Protocol) tools endpoints (/api/core/app/mcpTools/getTools and /api/core/app/mcpTools/runTool) accept a user-supplied URL parameter and make server-side HTTP requests to it without validating whether the URL points to an internal/private network address. Although the application has a dedicated isInternalAddress() function for SSRF protection (used in other endpoints like the HTTP workflow node), the MCP tools endpoints do not call this function. An authenticated attacker can use these endpoints to scan internal networks, access cloud metadata services, and interact with internal services such as MongoDB and Redis. This issue has been patched in version 4.14.9.5.

Key dates

02Disclosure timeline

March 31, 2026 CVE published
March 31, 2026 Record updated