From 67f3ff0c17d4c7da09fa530ef3a8941a68c06cbc Mon Sep 17 00:00:00 2001
From: Oskar Eichler <oskar@songstats.com>
Date: Sun, 30 Aug 2026 11:11:22 +0200
Subject: [PATCH] Fix EventEmitter prototype-key event types

---
 .../Libraries/vendor/emitter/EventEmitter.js  |  4 ++--
 .../emitter/__tests__/EventEmitter-itest.js   | 21 +++++++++++++++++++
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/packages/react-native/Libraries/vendor/emitter/EventEmitter.js b/packages/react-native/Libraries/vendor/emitter/EventEmitter.js
index 6014db5bd7c9..305965630f24 100644
--- a/packages/react-native/Libraries/vendor/emitter/EventEmitter.js
+++ b/packages/react-native/Libraries/vendor/emitter/EventEmitter.js
@@ -84,7 +84,7 @@ export default class EventEmitter<
 
   constructor() {
     // $FlowFixMe[incompatible-type]
-    this.#registry = {};
+    this.#registry = Object.create(null);
   }
 
   /**
@@ -147,7 +147,7 @@ export default class EventEmitter<
   ): void {
     if (eventType == null) {
       // $FlowFixMe[incompatible-type]
-      this.#registry = {};
+      this.#registry = Object.create(null);
     } else {
       // $FlowFixMe[cannot-write]
       delete this.#registry[eventType];
diff --git a/packages/react-native/Libraries/vendor/emitter/__tests__/EventEmitter-itest.js b/packages/react-native/Libraries/vendor/emitter/__tests__/EventEmitter-itest.js
index 7a746f0b47a5..dc0fb8b9f7e7 100644
--- a/packages/react-native/Libraries/vendor/emitter/__tests__/EventEmitter-itest.js
+++ b/packages/react-native/Libraries/vendor/emitter/__tests__/EventEmitter-itest.js
@@ -57,6 +57,27 @@ describe('listeners', () => {
     expect(listenerB).toHaveBeenCalledTimes(1);
   });
 
+  it('supports event types that match Object prototype keys', () => {
+    const emitter = new EventEmitter<Readonly<Record<string, []>>>();
+
+    const constructorListener = jest.fn();
+    const protoListener = jest.fn();
+    emitter.addListener('constructor', constructorListener);
+    emitter.addListener('__proto__', protoListener);
+
+    emitter.emit('constructor');
+    emitter.emit('__proto__');
+
+    expect(constructorListener).toHaveBeenCalledTimes(1);
+    expect(protoListener).toHaveBeenCalledTimes(1);
+    expect(emitter.listenerCount('constructor')).toBe(1);
+    expect(emitter.listenerCount('__proto__')).toBe(1);
+
+    emitter.removeAllListeners();
+    expect(emitter.listenerCount('constructor')).toBe(0);
+    expect(emitter.listenerCount('__proto__')).toBe(0);
+  });
+
   it('invokes listeners in registration order', () => {
     const emitter = new EventEmitter<{A: []}>();