Potential fix for code scanning alert no. 3: Prototype-polluting assignment (#3845)

* Potential fix for code scanning alert no. 3: Prototype-polluting assignment

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

* Change files

* Fix build issue

---------

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

Author: rurikoaraki

change/@fluentui-react-native-memo-cache-0c1ce6d7-722e-4518-9cf5-bc2fe0e0ced9.json

@@ -0,0 +1,7 @@
+{
+  "type": "patch",
+  "comment": "Potential fix for code scanning alert no. 3: Prototype-polluting assignment",
+  "packageName": "@fluentui-react-native/memo-cache",
+  "email": "ruaraki@microsoft.com",
+  "dependentChangeType": "patch"
+}

packages/framework/memo-cache/src/getCacheEntry.ts

@@ -22,6 +22,9 @@ export type CacheEntry<T, TGet = any> = {
  * @param key - which key of that entry to ensure the value for
  */
 function ensureAndReturn(entry: CacheEntry<any>, key: keyof CacheEntry<any>): CacheEntry<any> | { [key: string]: CacheEntry<any> } {
+  if ((key as string) === '__proto__' || (key as string) === 'constructor' || (key as string) === 'prototype') {
+    throw new Error('Invalid key');
+  }
   return (entry[key] = entry[key] || {});
 }