FastGPT — Vulnerability (CVE-2026-32128)
Date: 2026-03
Affected: fastgpt/fastgpt
Attack vector: other
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2026-32128
CWE: CWE-184
CVSS: 6.3 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L)

FastGPT is an AI Agent building platform. In 4.14.7 and earlier, FastGPT's Python Sandbox (fastgpt-sandbox) includes guardrails intended to prevent file writes (static detection + seccomp). These guardrails are bypassable by remapping stdout (fd 1) to an arbitrary writable file descriptor using fcntl. After remapping, writing via sys.stdout.write() still satisfies the seccomp rule write(fd==1), enabling arbitrary file creation/overwrite inside the sandbox container despite the intended no file writes restriction.


Mitigations:

Architectural layers (MAESTRO):