Flowise: Authenticated Host RCE via POST /api/v1/node-custom-function and NodeVM Sandbox Escape
CVE-2026-46442

9.4CRITICAL

Key Information:

Vendor

Flowiseai

Status
Flowise
Vendor
CVE Published:
8 June 2026

What is CVE-2026-46442?

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.

Affected Version(s)

Flowise < 3.1.2

References

https://github.com/FlowiseAI/Flowise/security/advisories/...
x_refsource_CONFIRM
https://github.com/FlowiseAI/Flowise/releases/tag/flowise...
x_refsource_MISC

CVSS V4

Score:
9.4
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.