CVE-2026-34163: labring FastGPT SSRF in MCP tools endpoints

CVE-2026-34163 · Severity: high · CVSS 7.7 · Published 2026-03-31

FastGPT, an AI agent building platform, contains a security flaw in its Model Context Protocol (MCP) tools. An authorized user can trick the system into making network requests to internal servers that should be private. This could allow an attacker to scan the company's internal network, access sensitive databases like MongoDB or Redis, or steal cloud service credentials, potentially leading to a broader data breach or service disruption.

Technologies: Fastgpt. Vendors: Fastgpt.

Quick answers

Is CVE-2026-34163 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-34163 being exploited in the wild.
How severe is CVE-2026-34163?
High severity, with a CVSS score of 7.7, published 31 March 2026.
Which products and versions are affected?
labring FastGPT < 4.14.9.5.
Is there a fix for CVE-2026-34163?
A patch was published on 2026-03-25: Fix committed and version 4.14.9.5 released. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-34163 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-34163?
Check whether you run Fastgpt. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A Server-Side Request Forgery (SSRF) vulnerability exists in FastGPT's MCP tools endpoints (/api/core/app/mcpTools/getTools and /api/core/app/mcpTools/runTool). These endpoints accept a user-supplied URL and initiate server-side HTTP/SSE requests via the MCPClient without validating if the target is an internal or private network address. While FastGPT includes an 'isInternalAddress()' validation function, it was not implemented on these specific routes. An authenticated attacker can exploit this to perform internal port scanning, interact with internal services like Redis and MongoDB, or access cloud metadata services (e.g., 169.254.169.254) to retrieve sensitive credentials. The issue is resolved in version 4.14.9.5 by enforcing internal address checks.

Affected products

  • labring FastGPT < 4.14.9.5

Timeline

  • 2026-03-25: patched: Fix committed and version 4.14.9.5 released.
  • 2026-03-26: advisory: Vendor security advisory published.
  • 2026-03-31: disclosed: CVE-2026-34163 published to NVD.

References

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