Vulnerability · Published Mar 31, 2026 · Assigned by GitHub_M

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

High 7.7

In plain English

A high-severity server-side request forgery in FastGPT from labring. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities).

Severity (CVSS 3.1)7.7High
Exploit odds (30 days)0.3%top 78.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

VendorProductVersions
labring FastGPT < 4.14.9.5

Weakness: CWE-918 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

References