Vulnerability Description
Flowise is a drag-and-drop user interface for building customized large language model (LLM) flows. Prior to version 3.1.3, several custom-tool components — AgentAsTool, ChatflowTool, and ExecuteFlow — ran code in the in-process vm2 sandbox. To build that code, they inserted a user-controlled baseURL value straight into the JavaScript source, for example const url = "${baseURL}/..."; . The only check on baseURL was isValidURL , but a valid-looking URL can still contain characters that break out of a code string. An authenticated user could craft a baseURL that passed this check, closed the surrounding string, and injected their own JavaScript into the sandboxed script (code injection, CWE-94). The vm2 sandbox runs in the same Node.js process as Flowise and exposes risky dependencies. As a result, the injected code could escape the sandbox and run arbitrary code on the Flowise server as the Flowise process user. Exploitation only requires an authenticated session. The issue is fixed in version 3.1.3, which passes the URL to the sandbox as data instead of inserting it into code and adds stricter URL validation.
Related Weaknesses (CWE)
References
- https://github.com/FlowiseAI/Flowise/commit/3f257bdc8196082a178da7134a075824401b
- https://github.com/FlowiseAI/Flowise/pull/6417
- https://github.com/FlowiseAI/Flowise/releases/tag/[email protected]
- https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-wg86-r78f-74mp
FAQ
What is CVE-2026-69253?
CVE-2026-69253 is a documented vulnerability. Flowise is a drag-and-drop user interface for building customized large language model (LLM) flows. Prior to version 3.1.3, several custom-tool components — AgentAsTool, ChatflowTool, and ExecuteFlow ...
How severe is CVE-2026-69253?
CVSS scoring is not yet available for CVE-2026-69253. Check NVD for updates.
Is there a patch for CVE-2026-69253?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.