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PRF Extension Not Supported in Safari's Cross-Device WebAuthn Flow
Safari 18.0.1 on macOS 15.01 doesn't support the Passkey PRF extension during cross-device WebAuthn authentication when using QR code scanning, while it works correctly with iCloud passkeys. Steps to Reproduce: Clone and setup: git clone https://github.com/quocle108/passkey-prf-test yarn yarn start Test iCloud Passkey Flow: Open http://localhost:3000 in Safari Open DevTools (Cmd+Option+I) Click "Register" Choose "Passkey on iCloud" Expected console output: PRF supported: true Test Cross-Device Flow: Click "Register" Choose "Phone/Tablet" Scan QR with mobile device Expected: PRF supported: true PRF extension should be supported in cross-device flow, matching iCloud passkey behavior. Actual: PRF supported: false Cross-device flow returns empty extension results. Verify in Chrome Repeat steps 2-3 in Chrome Both flows return proper PRF extension results: PRF supported: true Test Environment: Browser: Safari 18.1.1 , Chrome 131.0.6778.70 OS: macOS 15.01 Mobile: iOS 18.x / Galaxy Note9 Android 10 Test repo: https://github.com/quocle108/passkey-prf-test
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563
Mar ’25
Tab onDetached and Tab onAttached web extension events are no longer generated in macOS 15.4 / Safari 18.4
Hello - we have a Mac application that uses a browser extension and the web extension JS APIs to communicate with Safari. As of macOS 15.4 / Safari 18.4 the tab OnAttached and tab onDetached events are no longer received. After some testing we verified that the events were working properly as of macOS 15.3 / Safari 18.3 but appear to have been broken in macOS 15.4. Note a similar issue was reported previously for Safari 17.6 and was fixed in macOS 15.0 (FB14324177). We have made a TestFlight version of our app (Tabby) available to simplify debugging via https://testflight.apple.com/join/Va8Zdv9d. To reproduce the issue: Install the Tabby TestFlight build on macOS 15.4 or 15.4.1 Open Safari, go to Safari settings and select the Extensions tab Enable the Tabby extension and grant permissions to all windows all the time Open a Safari window with at least 3 tabs Note the open window and tabs displayed in Tabby In Safari, perform a tab detach by dragging a tab out of the window Expected behavior Within Safari the detached tab should now be in it’s own window, and via the onDetached event Tabby should update to show the tab in it’s own window AND removed from the original window. Observed Safari fails to send the onDetached event and Tabby will continue to display the detached tab in its original window in addition to the new window. You can also use the repro steps above to observe the onDetached event being received or not by Tabby in the Safari developer console. The same steps but re-attaching the tab to the original window can be used to observe the onAttached event being received or not. We’ve attached two screen recordings to the Feedback ID below, one showing the events working on macOS 15.3, and one showing the events failing to be received on macOS 15.4.1. Note it also fails on macOS 15.4. FEEDBACK ID: FB17367977
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146
May ’25
@@extension_id replacement in CSS file fails in Sequoia, Safari 18
Typically, you can use the @@extension_id special string to reference the absolute path into the bundled resources of an extension, such as an image or a custom font, in a CSS file. However, this broke with Safari 18. Consider this section in a popup.css file: .card-icon { height: 16px; width: 20px; background-image: url(safari-web-extension://__MSG_@@extension_id__/images/card.svg); background-size: 20px 16px; } In Safari 17.4, once loaded in the browser, @@extension_id is replaced with E8BEA491-9B80-45DB-8B20-3E586473BD47, and the background-image reads as so: background-image: url(safari-web-extension://E8BEA491-9B80-45DB-8B20-3E586473BD47/images/card.svg); But as of Safari 18, the @@extension_id just collapses to an empty string, and the background-image reads as so: background-image: url(safari-web-extension:///images/card.svg); and the svg fails to load with the following error: "Failed to load resource: You do not have permission to access the requested resource." This is a regression, does to match the behavior of the other major browsers, and should be fixed. Filed with Feedback ID: FB15104807
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853
Apr ’25
WKBrowsingContextController is invalid
Is this code invalid on a phone running xcode16 iOS18? Class cls = NSClassFromString(@"WKBrowsingContextController"); SEL sel = NSSelectorFromString(@"registerSchemeForCustomProtocol:"); if ([(id)cls respondsToSelector:sel]) { [(id)cls performSelector:sel withObject:@"http"]; [(id)cls performSelector:sel withObject:@"https"]; } }
Topic: Safari & Web SubTopic: General
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146
Jun ’25
header and footer positions shifted in Safari tab settings
Thank you for supporting me. My environment Device: iPhone 15 Pro OS: iOS 26.0 Public Beta (23A5336a) In iOS 26, three types of tabs were added to Safari. Depending on the option, the behavior of the fixed header and footer can be unstable. *Tab settings can be changed in the iOS Settings app under "Apps -> Safari" > "Tabs." The following behavior differs depending on the tab. Compact When scrolling down, the header and footer shift up by a few pixels. A margin is created between the footer and the URL input field. Bottom Behaves the same as "Compact." Top The header is completely hidden below the URL input field at the top of the screen, leaving a margin below the footer. Below is the sample code to check the operation. <!doctype html> <html lang="ja"> <head> <meta charset="utf-8" /> <meta name="viewport" content="width=device-width,initial-scale=1" /> <title>固定ヘッダー/フッター + モーダル</title> <style> :root { --header-h: 56px; --footer-h: 56px; } body { margin: 0; font-family: sans-serif; line-height: 1.6; background: #f9fafb; padding-top: var(--header-h); padding-bottom: var(--footer-h); } header .inner, footer .inner { width: 100%; max-width: var(--max-content-w); padding: 0 16px; display: flex; align-items: center; justify-content: space-between; } header, footer { position: fixed; left: 0; right: 0; display: flex; align-items: center; justify-content: center; z-index: 100; background: #fff; } header { top: 0; height: var(--header-h); border-bottom: 1px solid #ddd; } footer { bottom: 0; height: var(--footer-h); border-top: 1px solid #ddd; } main { padding: 16px; } .btn { padding: 8px 16px; border: 1px solid #2563eb; background: #2563eb; color: #fff; border-radius: 6px; cursor: pointer; } /* モーダル関連 */ .modal { position: fixed; inset: 0; display: none; z-index: 1000; } .modal.is-open { display: block; } .modal__backdrop { position: absolute; inset: 0; background: rgba(0,0,0,0.5); } .modal__panel { position: relative; max-width: 600px; margin: 10% auto; background: #fff; border-radius: 8px; padding: 20px; z-index: 1; } .modal__head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 12px; } .modal__title { margin: 0; font-size: 18px; font-weight: bold; } .modal__close { background: none; border: none; font-size: 20px; cursor: pointer; } </style> </head> <body> <header> <div class="inner"> <h1>デモページ</h1> <button id="openModal" class="btn">モーダルを開く</button> </div> </header> <main class="container" id="main"> <h2>スクロール用の適当なコンテンツ1</h2> <p>ヘッダーとフッターは常に表示されます。モーダルボタンを押すと、画面いっぱいのダイアログが開きます。</p> <!-- ダミーカードを複数 --> <section class="grid"> <div class="card"><strong>カード1</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード2</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード3</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード4</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード5</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード6</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード7</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード8</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード9</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> <div class="card"><strong>カード10</strong><p>適当なテキスト。適当なテキスト。適当なテキスト。</p></div> </section> </main> <footer> <small>&copy; 2025 Demo</small> </footer> <!-- モーダル --> <div class="modal" id="modal"> <div class="modal__backdrop"></div> <div class="modal__panel"> <div class="modal__head"> <h2 class="modal__title">モーダル</h2> <button class="modal__close" id="closeModal">&times;</button> </div> <p>これは白いビューのモーダルです。背景は黒く半透明で覆われています。</p> </div> </div> <script> const modal = document.getElementById('modal'); const openBtn = document.getElementById('openModal'); const closeBtn = document.getElementById('closeModal'); const backdrop = modal.querySelector('.modal__backdrop'); openBtn.addEventListener('click', () => { modal.classList.add('is-open'); }); function closeModal() { modal.classList.remove('is-open'); } closeBtn.addEventListener('click', closeModal); backdrop.addEventListener('click', closeModal); window.addEventListener('keydown', (e) => { if (e.key === 'Escape' && modal.classList.contains('is-open')) { closeModal(); } }); </script> </body> </html>
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827
Sep ’25
Safari Web Extension: This extension can read ... including passwords...
I want to migrate from a Safari App Extension to a Safari Web Extension, but don't know how to get rid of the message, telling users that my extension can access their passwords. Here is a message which I see: I was thinking that this might be because all Safari Web Extension get this type of access, but I have a Safari Web Extension which does not require such level of access: Here is the manifest: { "manifest_version": 2, "default_locale": "en", "name": "__MSG_extension_name__", "description": "__MSG_extension_description__", "version": "1.1", "icons": { "48": "images/icon-48.png" }, "background": { "scripts": [ "background.js" ], "persistent": true }, "browser_action": { "default_popup": "popup.html", "default_icon": { "16": "images/toolbar-icon-16.png" } }, "permissions": [ "nativeMessaging", "tabs" ] } and here is the Info.plist file: Here is the entire code of the extension: https://github.com/kopyl/web-extension-simplified
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521
Jan ’26
Adoption of New MV3 Standards for Browser Extensions
As with the adoption of MV3 standards among all major browser vendors that allow browser extensions at the client-side, I understand that this is the same with Safari as well, as mentioned here (https://www.wwdcnotes.com/notes/wwdc22/10099/). However, as with Firefox, browsers may choose to adopt them incompletely and with few changes. I had a few questions regarding how Safari views this transition and what would be the next steps from here. Thus, it would be really great if the browser team could provide your insights on any or all of the following points: Would Safari adopt the exact standards proposed by the Chromium ecosystem such as with functionalities like header-based modifications in the coming days.  What would be the general timeline be for this in general?  Does this also translate to the fact that existing standards with MV2 standards would not be allowed to operate any further, as with the timeline with Chromium? Regards
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2.0k
May ’25
WKNavigationAction.sourceFrame is nil on iOS 15.4 & 16.6 despite non-optional Swift declaration (fixed in iOS 18.6)
Reproducibility 100% on iOS 15.4 and iOS 16.6 Zero crash on iOS 18.6 Xcode 26.1 Steps to Reproduce Xcode 26.1 → New iOS App Replace ViewController.swift with the 20-line code below Run on real device • iPhone XR iOS 15.4 • iPhone 13 iOS 16.6 Tap the link → breakpoint in decidePolicyFor lldb → po navigationAction.sourceFrame Actual Result (lldb) po navigationAction.sourceFrame nil Swift declaration lies: public var sourceFrame: WKFrameInfo { get } // non-optional → Instant EXC_BREAKPOINT libswiftFoundation.dylib`URLRequest._unconditionallyBridgeFromObjectiveC Objective-C tells the truth: po [(WKNavigationAction *)navigationAction fixedSourceFrame] nil iOS 18.6 → same code prints a valid WKFrameInfo, no crash. Expected sourceFrame must be declared WKFrameInfo? in Swift or at least documented “can be nil on iOS 15–16”. Impact Every WKWebView app that touches sourceFrame on iOS 15.4 & 16.6 ships with a latent crash. Production Workaround @implementation WKNavigationAction (Safe) (WKFrameInfo *)fixedSourceFrame { return self.sourceFrame ? self.sourceFrame : nil; } @end Minimal Test (copy-paste) import UIKit import WebKit class ViewController: UIViewController, WKNavigationDelegate { lazy var web = WKWebView(frame: view.bounds) override func viewDidLoad() { super.viewDidLoad() web.navigationDelegate = self view.addSubview(web) web.load(URLRequest(url: URL(string: "https://www.apple.com")!)) } func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, preferences: WKWebpagePreferences, decisionHandler: @escaping (WKNavigationActionPolicy, WKWebpagePreferences)->Void) { print(navigationAction.sourceFrame) // ← crashes on 15.4 & 16.6 decisionHandler(.allow, preferences) } }
Topic: Safari & Web SubTopic: General Tags:
3
0
765
Nov ’25
[iOS 18.4 Beta 2-4] WKWebView content inset causes content touches to be off inside the web view
Background On iOS 18.4 beta, setting a content inset on a WKWebView causes touch events inside the web view to be offset by the content inset amount. In other words, if the web view has a top content inset of 75 points, I must tap 75 points above the intended element for the touch to register correctly. This makes any web content unusable when a content inset is present. A sample app demonstrating the issue is available here: GitHub - iOS18.4-Webview-Bug. The issue does not occur in iOS 18.3 or 18.2. Bug Report The bug has been reported and fixed at WebKit Bug 289715 and also filed as rdar://147075945. Question Will the fix be included in the upcoming iOS 18.4 beta release (Beta 5) or soon thereafter?
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294
Mar ’25
Web inspector only works with HTTPS contexts in iOS simulator
Up until some point relatively recently, I have been able to use Safari's web inspector to connect to the iOS simulator in order to debug our web application in development at http://localhost:8088. Now, the web inspector still OPENS, but it opens in a broken state. The context is available to select from Safari's "Develop" menu: Develop > "iPhone 16 Pro (Simulator)" > "localhost - login". It appears under the Safari heading if I have navigated to the web app in the browser, or under the Expo heading if I am accessing it through the webview in our React Native wrapper app. When I select it, the web inspector window does appear. However, once it opens, the Elements pane is empty, the Console pane is empty, expressions entered into the console are not evaluated, there's no content in Sources, Network, Storage, etc. Important notes: This broken state happens at http://localhost:8088 as well as http://127.0.0.1:8088, and it seems that the insecure context is the issue. The web inspector DOES work for HTTPS sites. If I navigate to, e.g., https://example.com in the simulator and connect the web inspector, everything works fine. The web inspector also works fine in Safari on macOS (OUTSIDE the simulator) when accessing non-HTTPS sites. It's only a problem for non-HTTPS sites when connecting to the simulator. A coworker has the same problem, so it is not isolated to my machine. I would enable TLS locally as a workaround, but this web app is very complex, and I know from experience that it is very difficult for various reasons to set it up properly for our project in development, and it will take significant non-trivial work to do so. So... Why is this happening? Is this expected behavior? Is there a way that I can debug my site on localhost without HTTPS?
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921
21h
How do I add a UI to a Safari Web Extension?
I have a Safari Web Extension that successfully receives a message from a webpage and returns a response. I now want to add a user interface to the Safari Web Extension. How do I do this? I have modified the default template code as follow to add an NSAlert for testing. The modal runs, but no alert ever appears, and the code remains stuck at runModal. What is the correct way to add a UI to a webextension? - (void)beginRequestWithExtensionContext:(NSExtensionContext *)context {     id message = [context.inputItems.firstObject userInfo][SFExtensionMessageKey];     NSLog(@"Received message from browser.runtime.sendNativeMessage: %@", message);     NSAlert* alert = [[NSAlert alloc]init];     [alert setMessageText:message[@"request"]];     [alert setInformativeText:@"Hello"];     [alert runModal];     NSExtensionItem *response = [[NSExtensionItem alloc] init];     response.userInfo = @{ SFExtensionMessageKey: @{ @"id": message[@"id"], @"uuid": message[@"uuid"], @"contentType": message[@"contentType"], @"response": message[@"request"] } };     [context completeRequestReturningItems:@[ response ] completionHandler:nil]; } @end
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1.2k
Mar ’25
What makes Safari render an active extension's icon in color in the toolbar?
Sometimes Safari is rendering the icon for an active extension in its original provided colored representation, other times Safari is applying an overlay color in line with the system's highlight color. This difference can even be seen seen on the Safari Extensions Developer home page: https://developer.apple.com/safari/extensions/images/extensions-hero-large_2x.png You will notice that Grammarly's icon is shown in it's original color format, while the others aren't. Example of extensions where the icon is shown in color: Bitwarden Grammarly 1Password Consent-O-Matic I've compared the source code of Bitwarden and Consent-o-Matic with my own extension and cannot find any differences in the settings or image properties (resolution, DPI, file type, color profile). If I take the exact PNG source files from said open source extensions and replace them in my own source code, these icons show up in full color. Does this perhaps mean there is a bug in Safari's processing of the icons where it fails to overlay the icon with the highlight color in some cases? I and I assume many developers with me would like to understand what determines this difference. Ideally, there is a consistent UX where the end user has the choice between icons in color or highlight color overlay.
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1.2k
Mar ’25
WKWebView crashes on iOS 26 with EXC_BAD_ACCESS
Hi, I have an app that uses WKWebView and it's crashing on iOS 26 Simulator in places I've never had problems before. In this case it's crashing when calling WKWebView.callAsyncJavaScript, but in my other project WKWebView is crashing with some sort of EXC_BAD_ACCESS other than callAsyncJavaScript. Am I missing something? Thanks,
Topic: Safari & Web SubTopic: General
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299
Jun ’25
iOS26 wkWebview Crash CALayer position contains NaN
On my native app, will open a wkWebview to display some content. And it will crash on iOS26: *** Terminating app due to uncaught exception 'CALayerInvalidGeometry', reason: 'CALayer position contains NaN: [nan 103.667]. Layer: <CALayer:0x14c2457d0; position = CGPoint (0 0); bounds = CGRect (0 0; 0 48); delegate = <_UIEditMenuListView: 0x14c273980; frame = (nan 0; 0 48); anchorPoint = (inf, 0); alpha = 0; layer = <CALayer: 0x14c2457d0>>; sublayers = (<CALayer: 0x1306320a0>, <CALayer: 0x14c245a70>); opaque = YES; allowsGroupOpacity = YES; anchorPoint = CGPoint (inf 0); opacity = 0>'
Topic: Safari & Web SubTopic: General Tags:
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465
Aug ’25
macOS 26 beta 4 and iOS 26 beta 4 - WebKit XML parser crashes parsing XHTML with namespaces
Our app, VitalSource Bookshelf, is an EPUB reader that uses a WKWebView to display book content. The EPUB content format is XHTML and uses namespaces (for the epub:type declaration). On beta 4, the webkit process repeatedly crashes when loading our content. The crash appears to be in the XML parser. Here's what's at the top of the stack trace: 0 WebCore 0x19166a878 WebCore::XMLDocumentParser::startElementNs(unsigned char const*, unsigned char const*, unsigned char const*, int, unsigned char const**, int, int, unsigned char const**) + 4968 1 libxml2.2.dylib 0x19c5a2bd0 xmlParseStartTag2 + 3940 2 libxml2.2.dylib 0x19c59e730 xmlParseTryOrFinish + 2984 3 libxml2.2.dylib 0x19c59d8e4 xmlParseChunk + 708 4 WebCore 0x191668ec8 WebCore::XMLDocumentParser::doWrite(WTF::String const&) + 636 5 WebCore 0x191665b78 WebCore::XMLDocumentParser::append(WTF::RefPtr<WTF::StringImpl, WTF::RawPtrTraits<WTF::StringImpl>, WTF::DefaultRefDerefTraits<WTF::StringImpl>>&&) + 304 6 WebCore 0x190105db0 WebCore::DecodedDataDocumentParser::appendBytes(WebCore::DocumentWriter&, std::__1::span<unsigned char const, 18446744073709551615ul>) + 268 7 WebCore 0x190861c3c WebCore::DocumentLoader::commitData(WebCore::SharedBuffer const&) + 1488 8 WebKit 0x18e07ca3c WebKit::WebLocalFrameLoaderClient::committedLoad(WebCore::DocumentLoader*, WebCore::SharedBuffer const&) + 52 9 WebCore 0x190869db4 WebCore::DocumentLoader::commitLoad(WebCore::SharedBuffer const&) + 228 10 WebCore 0x1909521e4 WebCore::CachedRawResource::notifyClientsDataWasReceived(WebCore::SharedBuffer const&) + 268 I was able to reproduce this in Safari on beta 4 just by opening the following trivial xhtml file from the file system - it does the same thing it does in our app, which is reloads and crashes several times, followed by the "A problem repeatedly occurred with..." error message. <?xml version="1.0" encoding="utf-8"?> <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml" xmlns:epub="http://www.idpf.org/2007/ops" epub:prefix="vst: http://vitalsource.com/"><head></head><body class="dash" epub:type="chapter" data-begin-o="0" data-begin-o2="0" data-begin-o3="0" data-o="0" id="eid1844" data-end-o="14703" data-end-o2="14703" data-end-o3="14703"><h2 class="title" data-o="0" id="eid1845" data-out="33"><span class="label" data-o="0" id="eid1846"><span class="label-inner"><b data-o="0" id="eid1847">CHAPTER X</b> </span></span>THE SUBMARINE COAL-MINES</h2></body></html> I've also filed a feedback. But posting here just to raise the visibility - this is critical for us. I think it was introduced in beta 4; that's at least when we first noticed it. It was working in the earlier betas, I just don't remember if I tried beta 3 or not. It happens on iOS, macOS, and iPadOS. This has never been a problem in any earlier release of macOS / iOS.
Topic: Safari & Web SubTopic: General
3
1
511
Aug ’25
SIGABRT on WebKit macOS 15.3.2
The application I'm currently working on uses WebKit. Based on the crash analytics, we have noticed that some of our users are experiencing an unusual behavior in the app's WebKit view with macOS 15.3.2. These errors are reported for this version of the OS. The error in the crash log is a SIGABRT error, but there is no relevant information available to address it. In some crash logs, we found this error: "NSInternalInconsistencyException: Returned WKWebView was not created with the given configuration" but there is not any particular way to address it. Is there a way to identify the cause of this error? Alternatively, has anyone encountered this issue and found a solution? OS Version: macOS 15.3.2 (24D81) Report Version: 104 Exception Type: EXC_CRASH (SIGABRT) Crashed Thread: 0 Application Specific Information: Returned WKWebView was not created with the given configuration. Thread 0 Crashed: 0 CoreFoundation 0x303111e74 __exceptionPreprocess 1 libobjc.A.dylib 0x3027b6cd4 objc_exception_throw 2 CoreFoundation 0x303111d6c +[NSException raise:format:] 3 WebKit 0x34e85cb20 WebKit::UIDelegate::UIClient::createNewPage 4 WebKit 0x34e8a4a80 WebKit::SOAuthorizationCoordinator::tryAuthorize 5 WebKit 0x34e9f04f8 WebKit::WebPageProxy::createNewPage 6 WebKit 0x34ef994c8 WebKit::WebPageProxy::didReceiveSyncMessage 7 WebKit 0x34f0830cc IPC::MessageReceiverMap::dispatchSyncMessage 8 WebKit 0x34ea753b0 WebKit::WebProcessProxy::didReceiveSyncMessage 9 WebKit 0x34f07cfb4 IPC::Connection::dispatchSyncMessage 10 WebKit 0x34f07d3b0 IPC::Connection::dispatchMessage 11 WebKit 0x34f078c50 IPC::Connection::SyncMessageState::ConnectionAndIncomingMessage::dispatch 12 WebKit 0x34f07f4f4 ***::Detail::CallableWrapper&lt;T&gt;::call 13 JavaScriptCore 0x33f3520c0 ***::RunLoop::performWork 14 JavaScriptCore 0x33f352fe8 ***::RunLoop::performWork 15 CoreFoundation 0x30309f8a0 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ 16 CoreFoundation 0x30309f834 __CFRunLoopDoSource0 17 CoreFoundation 0x30309f598 __CFRunLoopDoSources0 18 CoreFoundation 0x30309e134 __CFRunLoopRun 19 CoreFoundation 0x30309d730 CFRunLoopRunSpecific 20 HIToolbox 0x319aeb52c RunCurrentEventLoopInMode 21 HIToolbox 0x319af1344 ReceiveNextEventCommon 22 HIToolbox 0x319af1504 _BlockUntilNextEventMatchingListInModeWithFilter 23 AppKit 0x30a7cd844 _DPSNextEvent 24 AppKit 0x30b133c20 -[NSApplication(NSEventRouting) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] 25 AppKit 0x30a7c0870 -[NSApplication run] 26 AppKit 0x30a797064 NSApplicationMain 27 &lt;unknown&gt; 0x182780274 &lt;redacted&gt; Thread 0 name: t-main-ui Crashed: 0 CoreFoundation 0x303111e74 __exceptionPreprocess 1 libobjc.A.dylib 0x3027b6cd4 objc_exception_throw 2 CoreFoundation 0x303111d6c +[NSException raise:format:] 3 WebKit 0x34e85cb20 WebKit::UIDelegate::UIClient::createNewPage 4 WebKit 0x34e8a4a80 WebKit::SOAuthorizationCoordinator::tryAuthorize 5 WebKit 0x34e9f04f8 WebKit::WebPageProxy::createNewPage 6 WebKit 0x34ef994c8 WebKit::WebPageProxy::didReceiveSyncMessage 7 WebKit 0x34f0830cc IPC::MessageReceiverMap::dispatchSyncMessage 8 WebKit 0x34ea753b0 WebKit::WebProcessProxy::didReceiveSyncMessage 9 WebKit 0x34f07cfb4 IPC::Connection::dispatchSyncMessage 10 WebKit 0x34f07d3b0 IPC::Connection::dispatchMessage 11 WebKit 0x34f078c50 IPC::Connection::SyncMessageState::ConnectionAndIncomingMessage::dispatch 12 WebKit 0x34f07f4f4 ***::Detail::CallableWrapper&lt;T&gt;::call
3
0
210
Apr ’25
WKNavigationActionPolicy of "cancel" prints stack trace to console
Starting in iOS 26 (tested on 26.1), when I use any of the “policy” methods of WKNavigationDelegate to return an action policy of cancel I get a trace like this printed to console: 1 0x18de71bbc WebKit::WebFramePolicyListenerProxy::ignore(WebKit::WasNavigationIntercepted) 2 0x18db3dd50 WebKit::NavigationState::NavigationClient::decidePolicyForNavigationAction(WebKit::WebPageProxy&, WTF::Ref<API::NavigationAction, WTF::RawPtrTraits<API::NavigationAction>, WTF::DefaultRefDerefTraits<API::NavigationAction>>&&, WTF::Ref<WebKit::WebFramePolicyListenerProxy, WTF::RawPtrTraits<WebKit::WebFramePolicyListenerProxy>, WTF::DefaultRefDerefTraits<WebKit::WebFramePolicyListenerProxy>>&&)::$_0::operator()(WKNavigationActionPolicy, WKWebpagePreferences*) 3 0x100189e5c $sSo24WKNavigationActionPolicyVIeyBhy_ABIeghy_TR 4 0x100189d38 $s16WebkitPolicyTrap14ViewControllerC03webD0_06decideB3For15decisionHandlerySo05WKWebD0C_So18WKNavigationActionCySo0lmB0VctF 5 0x100189df4 $s16WebkitPolicyTrap14ViewControllerC03webD0_06decideB3For15decisionHandlerySo05WKWebD0C_So18WKNavigationActionCySo0lmB0VctFTo 6 0x18db255c0 WebKit::NavigationState::NavigationClient::decidePolicyForNavigationAction(WebKit::WebPageProxy&, WTF::Ref<API::NavigationAction, WTF::RawPtrTraits<API::NavigationAction>, WTF::DefaultRefDerefTraits<API::NavigationAction>>&&, WTF::Ref<WebKit::WebFramePolicyListenerProxy, WTF::RawPtrTraits<WebKit::WebFramePolicyListenerProxy>, WTF::DefaultRefDerefTraits<WebKit::WebFramePolicyListenerProxy>>&&) 7 0x18dea9848 WebKit::WebPageProxy::decidePolicyForNavigationAction(WTF::Ref<WebKit::WebProcessProxy, WTF::RawPtrTraits<WebKit::WebProcessProxy>, WTF::DefaultRefDerefTraits<WebKit::WebProcessProxy>>&&, WebKit::WebFrameProxy&, WebKit::NavigationActionData&&, WTF::CompletionHandler<void (WebKit::PolicyDecision&&)>&&) 8 0x18dea7a34 WebKit::WebPageProxy::decidePolicyForNavigationActionAsync(IPC::Connection&, WebKit::NavigationActionData&&, WTF::CompletionHandler<void (WebKit::PolicyDecision&&)>&&) 9 0x18d9cbbf4 void IPC::handleMessageAsync<Messages::WebPageProxy::DecidePolicyForNavigationActionAsync, IPC::Connection, WebKit::WebPageProxy, WebKit::WebPageProxy, void (IPC::Connection&, WebKit::NavigationActionData&&, WTF::CompletionHandler<void (WebKit::PolicyDecision&&)>&&)>(IPC::Connection&, IPC::Decoder&, WebKit::WebPageProxy*, void (WebKit::WebPageProxy::*)(IPC::Connection&, WebKit::NavigationActionData&&, WTF::CompletionHandler<void (WebKit::PolicyDecision&&)>&&)) 10 0x18d9c7728 WebKit::WebPageProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) 11 0x18e49a0d8 IPC::MessageReceiverMap::dispatchMessage(IPC::Connection&, IPC::Decoder&) 12 0x18df1908c WebKit::WebProcessProxy::dispatchMessage(IPC::Connection&, IPC::Decoder&) 13 0x18d9dfc28 WebKit::WebProcessProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) 14 0x18e47f72c IPC::Connection::dispatchMessage(WTF::UniqueRef<IPC::Decoder>) 15 0x18e47fac4 IPC::Connection::dispatchIncomingMessages() 16 0x199ad3758 WTF::RunLoop::performWork() 17 0x199ad4eb0 WTF::RunLoop::performWork(void*) 18 0x1804563a4 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ 19 0x1804562ec __CFRunLoopDoSource0 20 0x180455a78 __CFRunLoopDoSources0 21 0x180454c4c __CFRunLoopRun 22 0x18044fcec _CFRunLoopRunSpecificWithOptions 23 0x1926be9bc GSEventRunModal 24 0x18630f0d8 -[UIApplication _run] 25 0x186313300 UIApplicationMain 26 0x18554ac38 block_destroy_helper.15 27 0x10018a70c $sSo21UIApplicationDelegateP5UIKitE4mainyyFZ 28 0x10018a67c $s16WebkitPolicyTrap11AppDelegateC5$mainyyFZ 29 0x10018a818 __debug_main_executable_dylib_entry_point 30 0x1000cd3d0 29 dyld 0x00000001000cd3d0 start_sim + 20 31 0x1002bab98 30 ??? 0x00000001002bab98 0x0 + 4297829272 This doesn’t happen in 18.6. Also, it doesn’t seem to have any negative consequences other than the console spam? But then, the navigation is being cancelled anyway, so maybe it’s trapping and just happens to have the effect of not loading the request? Anyway, I guess I can’t upload zips. But it’s pretty easy to reproduce. Just assign a WKWebView a navigationDelegate with an implementation like: func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping @MainActor (WKNavigationActionPolicy) -> Void) { decisionHandler(.cancel) } and then have it .load() anything. Have I been doing this wrong and 26 exposes it? Or is this a bug in 26? If the latter, any downstream consequences I should be looking out for? macOS 15.7.1 (24G231) Xcode 26.1.1 (17B100) iOS 26.1 (23B86)
Topic: Safari & Web SubTopic: General Tags:
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Dec ’25