Flowise Sandbox Escape to RCE

============================================================================= Security Advisory elttam Topic: Flowise JavaScript Sandbox Escape Module: FlowiseAI/Flowise, FlowiseAI/nodevm Disclosed: 11-Apr-2026 Credits: Luke Jahnke and Alex Brown Affects: FlowiseAI/Flowise 3.1.1, FlowiseAI/nodevm...

CVE-2026-47141

vm2 is an open source vm/sandbox for Node.js. Prior to version 3.11.4, NodeVM exposes some process-wide observability builtins when they are allowed through require.builtin. The diagnosticschannel, asynchooks, and perfhooks builtins are not blocked by the dangerous builtin denylist. These modules...

CVE-2026-47141

CVE-2026-47141 affects vm2 NodeVM where diagnostics_channel, async_hooks, and perf_hooks observability builtins were exposed to sandboxed code before patching in vm2 3.11.4. These process‑wide modules can leak host data (e.g., HTTP headers, AsyncResource state, performance entries) into the sandb...

CVE-2026-47141 vm2: NodeVM observability builtins leak host process and HTTP request data

vm2 is an open source vm/sandbox for Node.js. Prior to version 3.11.4, NodeVM exposes some process-wide observability builtins when they are allowed through require.builtin. The diagnosticschannel, asynchooks, and perfhooks builtins are not blocked by the dangerous builtin denylist. These modules...

CVE-2026-47140

vm2 is an open source vm/sandbox for Node.js. Prior to version 3.11.4, NodeVM blocks several dangerous Node.js builtins such as module, workerthreads, cluster, vm, repl, and inspector. However, the denylist misses process and inspector/promises. Both can be used from sandboxed code to reach...

CVE-2026-47139

vm2 NodeVM burlon bypass vulnerability exists where public network modules are blocked but internal underscored HTTP builtins (_http_client, _http_server) remain reachable. The issue allows sandboxed code to perform outbound HTTP requests and open listening sockets despite network exclusions, ena...

CVE-2026-47139 vm2: NodeVM network builtin exclusions bypass via internal _http_client and _http_server

vm2 is an open source vm/sandbox for Node.js. Prior to version 3.11.4, NodeVM supports excluding public network builtins from the wildcard builtin option. With this configuration direct access to http, https, http2, net, dgram, tls, dns, and dns/promises is blocked. However, Node.js also exposes...

CVE-2026-47141: Exposure of Resource to Wrong Sphere

vm2 is an open source vm/sandbox for Node.js. Prior to version 3.11.4, NodeVM exposes some process-wide observability builtins when they are allowed through require.builtin. The diagnosticschannel, asynchooks, and perfhooks builtins are not blocked by the dangerous builtin denylist. These modules...

CVE-2026-47139: Protection Mechanism Failure

vm2 is an open source vm/sandbox for Node.js. Prior to version 3.11.4, NodeVM supports excluding public network builtins from the wildcard builtin option. With this configuration direct access to http, https, http2, net, dgram, tls, dns, and dns/promises is blocked. However, Node.js also exposes...

CVE-2026-47140: Protection Mechanism Failure

vm2 is an open source vm/sandbox for Node.js. Prior to version 3.11.4, NodeVM blocks several dangerous Node.js builtins such as module, workerthreads, cluster, vm, repl, and inspector. However, the denylist misses process and inspector/promises. Both can be used from sandboxed code to reach...

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...

CVE-2026-46442: Improper Control of Generation of Code

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...

Protection Mechanism Failure

Overview org.webjars.npm:vm2 is a sandbox that can run untrusted code with whitelisted Node's built-in modules. Affected versions of this package are vulnerable to Protection Mechanism Failure through the NodeVM builtin wildcard expansion in lib/builtin.js. An attacker can load Node’s private...

NodeVM network builtin exclusions bypass via internal _http_client and _http_server

Summary NodeVM supports excluding public network builtins from the wildcard builtin option. With this configuration direct access to http, https, http2, net, dgram, tls, dns, and dns/promises is blocked. However, Node.js also exposes underscored internal HTTP builtins such as httpclient and...

Improper Control of Dynamically-Managed Code Resources

Overview org.webjars.npm:vm2 is a sandbox that can run untrusted code with whitelisted Node's built-in modules. Affected versions of this package are vulnerable to Improper Control of Dynamically-Managed Code Resources through the NodeVM constructor in lib/nodevm.js. An attacker can obtain host...

vm2 has a CVE-2023-37903 patch bypass: nesting:true without explicit require still allows full RCE

Summary The fix for GHSA-8hg8-63c5-gwmx CVE-2023-37903 introduced a check in nodevm.js line 263 that blocks the combination nesting: true + require: false. However, the check uses strict equality options.require === false, which is trivially bypassed by omitting the require option entirely. When...

Improper Control of Dynamically-Managed Code Resources

Overview vm2 is a sandbox that can run untrusted code with whitelisted Node's built-in modules. Affected versions of this package are vulnerable to Improper Control of Dynamically-Managed Code Resources through the NodeVM constructor in lib/nodevm.js. An attacker can obtain host code execution by...

GHSA-M4WX-M65X-GHRR vm2 has a CVE-2023-37903 patch bypass: nesting:true without explicit require still allows full RCE

Summary The fix for GHSA-8hg8-63c5-gwmx CVE-2023-37903 introduced a check in nodevm.js line 263 that blocks the combination nesting: true + require: false. However, the check uses strict equality options.require === false, which is trivially bypassed by omitting the require option entirely. When...

NPM: FlowiseAI: Authenticated Host RCE via POST /api/v1/node-custom-function and NodeVM Sandbox Escape

NPM: FlowiseAI: Authenticated Host RCE via POST /api/v1/node-custom-function and NodeVM Sandbox Escape vulnerability discovered by ? in WordPress Npm flowise versions = 3.1.1...

GHSA-9RVC-VF7M-PGM2 FlowiseAI: Authenticated Host RCE via POST /api/v1/node-custom-function and NodeVM Sandbox Escape

Summary 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 E2BAPIKEY is not configured — the common deployment case — Flowise executes this code inside a NodeVM sandbox...