CVE-2026-32128
These guardrails are bypassable by remapping stdout (fd 1) to an arbitrary writable file descriptor using fcntl.
Does this matter?
Lower severity and a low EPSS score (0.30%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 6.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
- EPSS
- 0.30% probability · 22th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-184
- Affected
- fastgpt/fastgpt
- Source
- security-advisories@github.com
References
- https://github.com/labring/FastGPT/security/advisories/GHSA-6hw6-mxrm-v6wjExploit, Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.