CVE-2026-32128: FastGPT Python Sandbox Bypass of File-Write Restriction
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.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-32128?
CVE-2026-32128 is considered to have a medium severity due to its potential to bypass file-write restrictions.
How do I fix CVE-2026-32128?
To fix CVE-2026-32128, upgrade to FastGPT version 4.14.8 or later where the vulnerability has been patched.
What software is affected by CVE-2026-32128?
CVE-2026-32128 affects FastGPT versions up to 4.14.7, specifically the fastgpt-sandbox component.
What type of vulnerability is CVE-2026-32128?
CVE-2026-32128 is a sandbox bypass vulnerability that compromises file-write restrictions in the Python environment.
Can CVE-2026-32128 be exploited remotely?
CVE-2026-32128 can potentially be exploited locally by remapping stdout, allowing unauthorized file write operations.