Flowise is a drag & drop user interface to build a customized large language model flow. Prior to version 3.1.2, POST /api/v1/node-custom-function lacks route-level authorization, allowing any authenticated user or API key to submit arbitrary JavaScript to the Custom JS Function node. When E2B_APIKEY is not configured — the common deployment case — Flowise executes this code inside a NodeVM sandbox. This sandbox can be escaped, allowing an attacker to reach the host process object and execute system commands via child_process. The result is authenticated remote code execution on the Flowise server host. This issue has been patched in version 3.1.2.
https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-9rvc-vf7m-pgm2
https://github.com/FlowiseAI/Flowise/releases/tag/flowise%403.1.2
Published: 2026-06-08
Updated: 2026-06-08
Base Score: 6.5
Vector: CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:P
Severity: Medium
Base Score: 9.9
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Severity: Critical
Base Score: 9.4
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
Severity: Critical