Skip to content
Fencer Intel
medium 6.3

CVE-2026-44287 json

FastGPT: sandbox escape to RCE - code-sandbox regex /\bimport\s*\(/ is bypassable

published 5mo ago modified 3mo ago also EUVD-2026-33431

cvss
6.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits
0
none known

Summary

FastGPT is an AI Agent building platform. Prior to 4.15.0-beta1, the JavaScript sandbox worker at projects/code-sandbox/src/pool/worker.ts:356 blocks dynamic import() with the regex /\bimport\s*\(/.test(code). JavaScript syntax accepts a block comment between import and (; the regex matches only ASCII whitespace, and the bytes /, *, *, / are not in the \s character class. The payload import/**/("child_process") parses as a syntactically valid dynamic import that the regex does not detect. Because import() is not wrapped by the safeRequire Proxy (which only proxies require), the attacker loads child_process and calls execSync - arbitrary command execution as uid=100(sandbox) inside the sandbox container. This vulnerability is fixed in 4.15.0-beta1.

Patch / fix

  • fastgpt fastgpt 4.15.0-beta1

Is CVE-2026-44287 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
5mo ago

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/labring/FastGPT/security/advisories/GHSA-f5mq-qxm4-5mvc referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 6.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

Affected products

  • labring FastGPT

Classification

Weakness
  • CWE-94 Improper Control of Generation of Code
  • CWE-184 Incomplete List of Disallowed Inputs

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.