Flowise through 3.1.4 Custom Function Sandbox Escape RCE via LocalFileStore

Advisories

Flowise through 3.1.4 Custom Function Sandbox Escape RCE via LocalFileStore

Severity: critical
Date: 10/30/2026
Affecting: Flowise <= 3.1.4
CVE: CVE-2026-119978
CWE: CWE-749 Exposed Dangerous Method or Function
CVSS: 9.0
CVSS V4 Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
References: https://github.com/FlowiseAI/Flowise/blob/a65f81bb43ef66d3ce734bf0dff4223ae8041c95/packages/components/src/utils.ts#L55-L114
https://github.com/FlowiseAI/Flowise/blob/a65f81bb43ef66d3ce734bf0dff4223ae8041c95/packages/components/src/utils.ts#L1733
GitHub Security Advisory (GHSA-9gvv-qjj3-2p6g)
https://github.com/FlowiseAI/Flowise
Credit: soovwv
Description: Flowise through 3.1.4 contains a sandbox escape vulnerability that allows authenticated users to execute OS commands by abusing allowlisted langchain and mammoth modules when ALLOW_BUILTIN_DEP=true. Attackers can submit JavaScript to /api/v1/node-custom-function that writes a file into the mammoth package via LocalFileStore and requires it, escaping vm2 as the Flowise process user.

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