fix/unbound fetch

.pubnub.yml

@@ -1,5 +1,10 @@
 ---
 changelog:
+  - date: 2026-07-27
+    version: v12.0.3
+    changes:
+      - type: bug
+        text: "Fixes unbound fetch issue."
   - date: 2026-07-22
     version: v12.0.2
     changes:
@@ -1437,7 +1442,7 @@ supported-platforms:
       - 'Ubuntu 14.04 and up'
       - 'Windows 7 and up'
     version: 'Pubnub Javascript for Node'
-version: '12.0.2'
+version: '12.0.3'
 sdks:
   - full-name: PubNub Javascript SDK
     short-name: Javascript
@@ -1453,7 +1458,7 @@ sdks:
           - distribution-type: source
             distribution-repository: GitHub release
             package-name: pubnub.js
-            location: https://github.com/pubnub/javascript/archive/refs/tags/v12.0.2.zip
+            location: https://github.com/pubnub/javascript/archive/refs/tags/v12.0.3.zip
             requires:
               - name: 'agentkeepalive'
                 min-version: '3.5.2'
@@ -2124,7 +2129,7 @@ sdks:
           - distribution-type: library
             distribution-repository: GitHub release
             package-name: pubnub.js
-            location: https://github.com/pubnub/javascript/releases/download/v12.0.2/pubnub.12.0.2.js
+            location: https://github.com/pubnub/javascript/releases/download/v12.0.3/pubnub.12.0.3.js
             requires:
               - name: 'agentkeepalive'
                 min-version: '3.5.2'

CHANGELOG.md

@@ -1,3 +1,9 @@
+## v12.0.3
+July 27 2026
+
+#### Fixed
+- Fixes unbound fetch issue.
+
 ## v12.0.2
 July 22 2026
 

README.md

@@ -27,8 +27,8 @@ Watch [Getting Started with PubNub JS SDK](https://app.dashcam.io/replay/64ee0d2
      npm install pubnub
      ```
    * or download one of our builds from our CDN: 
-     * https://cdn.pubnub.com/sdk/javascript/pubnub.12.0.2.js
-     * https://cdn.pubnub.com/sdk/javascript/pubnub.12.0.2.min.js
+     * https://cdn.pubnub.com/sdk/javascript/pubnub.12.0.3.js
+     * https://cdn.pubnub.com/sdk/javascript/pubnub.12.0.3.min.js
 
    > **React Native:** the SDK relies on a global `URL` implementation, which React Native does not
    > provide, so it depends on [`react-native-url-polyfill`](https://www.npmjs.com/package/react-native-url-polyfill).

dist/web/pubnub.js

@@ -5477,7 +5477,7 @@
 	            return base.PubNubFile;
 	        },
 	        get version() {
-	            return '12.0.2';
+	            return '12.0.3';
 	        },
 	        getVersion() {
 	            return this.version;
@@ -6272,8 +6272,12 @@
 	        // no `document`, and `fetch` cannot be reached through a fresh browsing context — return the context `fetch`
 	        // directly. This is safe there: without a DOM there is no APM page script to monkey patch `fetch` in the
 	        // first place. This environment check is what keeps the unconditional call in the constructor safe.
+	        //
+	        // `fetch` must be bound to the global scope: native `fetch` requires its `this` to be the `Window` /
+	        // `WorkerGlobalScope`, and it is later invoked detached (`WebTransport.originalFetch(...)`). Without the bind
+	        // a service worker throws "Failed to execute 'fetch' on 'WorkerGlobalScope': Illegal invocation".
 	        if (typeof document === 'undefined' || !document.body)
-	            return fetch;
+	            return fetch.bind(globalThis);
 	        let iframe = document.querySelector('iframe[name="pubnub-context-unpatched-fetch"]');
 	        if (!iframe) {
 	            iframe = document.createElement('iframe');
@@ -6284,7 +6288,7 @@
 	        }
 	        if (iframe.contentWindow)
 	            return iframe.contentWindow.fetch.bind(iframe.contentWindow);
-	        return fetch;
+	        return fetch.bind(globalThis);
 	    }
 	}
 	/**

lib/core/components/configuration.js

@@ -174,7 +174,7 @@ const makeConfiguration = (base, setupCryptoModule) => {
             return base.PubNubFile;
         },
         get version() {
-            return '12.0.2';
+            return '12.0.3';
         },
         getVersion() {
             return this.version;

package.json

@@ -1,6 +1,6 @@
 {
   "name": "pubnub",
-  "version": "12.0.2",
+  "version": "12.0.3",
   "author": "PubNub <support@pubnub.com>",
   "description": "Publish & Subscribe Real-time Messaging with PubNub",
   "scripts": {

src/core/components/configuration.ts

@@ -245,7 +245,7 @@ export const makeConfiguration = (
       return base.PubNubFile;
     },
     get version(): string {
-      return '12.0.2';
+      return '12.0.3';
     },
     getVersion(): string {
       return this.version;

src/transport/web-transport.ts

@@ -444,7 +444,11 @@ export class WebTransport implements Transport {
     // no `document`, and `fetch` cannot be reached through a fresh browsing context — return the context `fetch`
     // directly. This is safe there: without a DOM there is no APM page script to monkey patch `fetch` in the
     // first place. This environment check is what keeps the unconditional call in the constructor safe.
-    if (typeof document === 'undefined' || !document.body) return fetch;
+    //
+    // `fetch` must be bound to the global scope: native `fetch` requires its `this` to be the `Window` /
+    // `WorkerGlobalScope`, and it is later invoked detached (`WebTransport.originalFetch(...)`). Without the bind
+    // a service worker throws "Failed to execute 'fetch' on 'WorkerGlobalScope': Illegal invocation".
+    if (typeof document === 'undefined' || !document.body) return fetch.bind(globalThis);
 
     let iframe = document.querySelector<HTMLIFrameElement>('iframe[name="pubnub-context-unpatched-fetch"]');
 
@@ -457,6 +461,6 @@ export class WebTransport implements Transport {
     }
 
     if (iframe.contentWindow) return iframe.contentWindow.fetch.bind(iframe.contentWindow);
-    return fetch;
+    return fetch.bind(globalThis);
   }
 }