CVE-2026-44287: FastGPT: sandbox escape to RCE - code-sandbox regex /\bimport\s*\(/ is bypassable

Severity: medium (CVSS 6.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-29 · updated 2026-07-22
Weakness: CWE-94

Description

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.

Affected products

labring FastGPT: before 4.15.0-beta1

References

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