Astro Cloudflare adapter has a Stored Cross Site Scripting vulnerability in /_image endpoint

@@ -0,0 +1,23 @@
+---
+'@astrojs/internal-helpers': patch
+'astro': patch
+---
+
+Changes the remote protocol checks for images to require explicit authorization in order to use data URIs.
+
+In order to allow data URIs for remote images, you will need to update your `astro.config.mjs` file to include the following configuration:
+
+```js
+// astro.config.mjs
+import { defineConfig } from 'astro/config';
+
+export default defineConfig({
+  images: {
+    remotePatterns: [
+      {
+        protocol: 'data',
+      },
+    ],
+  },
+});
+```

@@ -26,6 +26,11 @@ describe('astro:image', () => {
 				image: {
 					service: testImageService({ foo: 'bar' }),
 					domains: ['avatars.githubusercontent.com'],
+					remotePatterns: [
+						{
+							protocol: 'data',
+						},
+					],
 				},
 			});
 

@@ -1,6 +1,7 @@
 import * as assert from 'node:assert/strict';
 import { describe, it } from 'node:test';
 import {
+	isRemoteAllowed,
 	matchHostname,
 	matchPathname,
 	matchPattern,
@@ -13,6 +14,7 @@ describe('remote-pattern', () => {
 	const url2 = new URL('http://preview.docs.astro.build:8080/');
 	const url3 = new URL('https://astro.build/');
 	const url4 = new URL('https://example.co/');
+	const url5 = new URL('data:text/plain;base64,SGVsbG8sIFdvcmxkIQ==');
 
 	describe('remote pattern matchers', () => {
 		it('matches protocol', async () => {
@@ -22,6 +24,7 @@ describe('remote-pattern', () => {
 			// defined, true/false
 			assert.equal(matchProtocol(url1, 'http'), false);
 			assert.equal(matchProtocol(url1, 'https'), true);
+			assert.equal(matchProtocol(url5, 'data'), true);
 		});
 
 		it('matches port', async () => {
@@ -123,6 +126,36 @@ describe('remote-pattern', () => {
 				}),
 				false,
 			);
+
+			assert.equal(
+				matchPattern(url5, {
+					protocol: 'data',
+				}),
+				true,
+			);
+		});
+	});
+
+	describe('remote is allowed', () => {
+		it('allows remote URLs based on patterns', async () => {
+			const patterns = {domains: [], remotePatterns: [
+				{
+					protocol: 'https',
+					hostname: '**.astro.build',
+					pathname: '/en/**',
+				},
+				{
+					protocol: 'http',
+					hostname: 'preview.docs.astro.build',
+					port: '8080',
+				},
+			]};
+
+			assert.equal(isRemoteAllowed(url1, patterns), true);
+			assert.equal(isRemoteAllowed(url2, patterns), true);
+			assert.equal(isRemoteAllowed(url3, patterns), false);
+			assert.equal(isRemoteAllowed(url4, patterns), false);
+			assert.equal(isRemoteAllowed(url5, patterns), false);
 		});
 	});
 });

@@ -128,13 +128,8 @@ export function isRemoteAllowed(
 
 	const url = new URL(src);
 
-	// Data URLs are always allowed
-	if (url.protocol === 'data:') {
-		return true;
-	}
-
 	// Non-http(s) protocols are never allowed
-	if (!['http:', 'https:'].includes(url.protocol)) {
+	if (!['http:', 'https:', 'data:'].includes(url.protocol)) {
 		return false;
 	}