Sandbox Escape Vulnerability in Flowise by FlowiseAI

CVE-2026-119978

What is CVE-2026-119978?

The Flowise software up to version 3.1.4 is susceptible to a sandbox escape vulnerability that allows authenticated users to execute arbitrary OS commands. This exploit occurs when the configuration allows the use of certain langchain and mammoth modules. Specifically, when the ALLOW_BUILTIN_DEP is set to true, attackers can leverage the JavaScript submission to the /api/v1/node-custom-function endpoint, enabling them to write files into the mammoth package using the LocalFileStore method. This capability ultimately allows them to escape the protective environment provided by vm2, executing commands as the user running the Flowise process.

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