From 00dbd9454ae87f8ebaff0a48a01c7d71a78c80ee Mon Sep 17 00:00:00 2001
From: Andre Alves <andremralves@gmail.com>
Date: Fri, 11 Aug 2023 01:47:22 -0300
Subject: [PATCH] lib: fix MIME overmatch in data URLs

This commit adds the delimiters ^ and $ to the regex that matches the
MIME types for "data:URLs".
Fixes: https://github.com/nodejs/node/issues/48957
---
 lib/internal/modules/esm/formats.js          | 2 +-
 test/es-module/test-esm-invalid-data-urls.js | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/internal/modules/esm/formats.js b/lib/internal/modules/esm/formats.js
index 63742914597c46..c4181b50f10451 100644
--- a/lib/internal/modules/esm/formats.js
+++ b/lib/internal/modules/esm/formats.js
@@ -26,7 +26,7 @@ if (experimentalWasmModules) {
 function mimeToFormat(mime) {
   if (
     RegExpPrototypeExec(
-      /\s*(text|application)\/javascript\s*(;\s*charset=utf-?8\s*)?/i,
+      /^\s*(text|application)\/javascript\s*(;\s*charset=utf-?8\s*)?$/i,
       mime,
     ) !== null
   ) return 'module';
diff --git a/test/es-module/test-esm-invalid-data-urls.js b/test/es-module/test-esm-invalid-data-urls.js
index e434c895a2e37d..6eafe75e7d7ed7 100644
--- a/test/es-module/test-esm-invalid-data-urls.js
+++ b/test/es-module/test-esm-invalid-data-urls.js
@@ -18,4 +18,7 @@ const assert = require('assert');
     code: 'ERR_UNKNOWN_MODULE_FORMAT',
     message: 'Unknown module format: text/css for URL data:text/css,.error { color: red; }',
   });
+  await assert.rejects(import('data:WRONGtext/javascriptFORMAT,console.log("hello!");'), {
+    code: 'ERR_UNKNOWN_MODULE_FORMAT',
+  });
 })().then(common.mustCall());