FastGPT Python Sandbox Bypass of File-Write Restriction

Description

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.

Scores

EPSS (exploitation in 30 days)

0.35% · top 72% of all CVEs (6 Nov 2026)

CISA SSVC

Exploitation: poc · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.3.

Weakness

• CWE-184: Incomplete List of Disallowed Inputs (opens in a new tab)All about CWE-184 and its CVEs

Affected products

• labring · FastGPT

  • affected <= 4.14.7

References (1)

• https://github.com/labring/FastGPT/security/advisories/GHSA-6hw6-mxrm-v6wj (opens in a new tab)x_refsource_CONFIRM

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-32128](https://trackcve.app/badge/CVE-2026-32128.svg)](https://trackcve.app/cve/CVE-2026-32128)

Record last updated 12 Mar 2026, 16:18 UTC.