FastGPT — Ssrf (CVE-2026-40100)
Date: 2026-04
Affected: fastgpt/fastgpt
Attack vector: ssrf
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2026-40100
CWE: CWE-918
CVSS: 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N)

FastGPT is an AI Agent building platform. Prior to 4.14.10.3, the /api/core/app/mcpTools/runTool endpoint accepts arbitrary URLs without authentication. The internal IP check in isInternalAddress() only blocks private IPs when CHECK_INTERNAL_IP=true, which is not the default. This allows unauthenticated attackers to perform SSRF against internal network resources. This vulnerability is fixed in 4.14.10.3.


Mitigations:

Architectural layers (MAESTRO):