Description

Locutus vulnerable to RCE via unsanitized input in create_function()

Summary

The create_function(args, code) function passes both parameters directly to the Function constructor without any sanitization, allowing arbitrary code execution.

This is distinct from CVE-2026-29091 (GHSA-fp25-p6mj-qqg6) which was call_user_func_array using eval() in v2.x. This finding affects create_function using new Function() in v3.x.

Root Cause

src/php/funchand/create_function.ts:17:

return new Function(...params, code)

Zero input validation on either parameter.

PoC

const { create_function } = require('locutus/php/funchand/create_function');
const rce = create_function('', 'return require("child_process").execSync("id").toString()');
console.log(rce());
// Output: uid=501(user) gid=20(staff) ...

Confirmed on locutus v3.0.11, Node.js v24.13.1.

Impact

Full RCE when an attacker can control either argument to create_function(). 597K weekly npm downloads.

Suggested Fix

Remove create_function or replace new Function() with a safe alternative. PHP itself deprecated create_function() in PHP 7.2 for the same reason.

Response

Thanks for the report.

We confirmed that php/funchand/create_function was still present through [email protected] and that it exposed dynamic code execution via new Function(...).

While this was intended behavior, create_function() inherently needs to be unsafe in order for it to work, create_function() was deprecated in PHP 7.2 and removed in PHP 8.0. Given that Locutus' parity target today is 8.3, this function shouldn't have been in Locutus at all anymore.

We fixed this in [email protected] by removing php/funchand/create_function entirely. That matches our PHP 8.3 parity target more closely: .

We also updated php/var/var_export so closures now export using the PHP 8-style \Closure::__set_state(array(...)) form instead of referencing the removed API.

Release:

npm: [email protected]

GitHub release: https://github.com/locutusjs/locutus/releases/tag/v3.0.14

Credit to @ByamB4 for the report.

Mitigation

Aliases

References