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WebSocket connection instantly closes (FIN) on iPadOS 26 in PWA (Local HTTP/WS)
I am maintaining a PWA that utilizes WebSockets. In this app, after the web page is loaded from the server, JavaScript establishes a WebSocket connection. Because the app connects to a completely local server on a managed local network, we use http:// and ws:// (non-secure). The Issue: The app worked perfectly from older iOS versions up to iPadOS 18. However, during testing on iPadOS 26, we encountered an issue where the WebSocket connects successfully but is disconnected by the iPad approximately one second later. According to our packet captures, the iPad is sending a FIN packet to initiate the teardown. Additional Context: What makes this particularly confusing is that we have another server hosting the exact same PWA where the WebSocket connection stays stable even on iPadOS 26. This suggests it might not be a universal OS bug, but perhaps related to specific network conditions or a new security policy. Has anyone experienced similar behavior on iPadOS 26? Could this be a bug, or is there a new security restriction regarding non-secure WebSocket (ws://) connections in local networks? Are there any known changes in WebKit/Safari for iPadOS 26 that might cause the OS to send a FIN packet immediately after a handshake? I would appreciate any insights or suggestions on what might be causing this.
Topic: Safari & Web SubTopic: General
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Safari Web Extension tab ids are 0 during webNavigation callbacks until onCompleted event
Safari Version 14.0.1 (16610.2.11.51.8) I am porting a Chrome/Firefox/Edge extension to Safari Web Extension. Mostly, the process was painless, I am, however, seeing quite different behavior in the tab ids generated by Safari compared to Chrome, Firefox, and Edge. My extension has callbacks for each of these browser.webNavigation events: browser.webNavigation.onBeforeNavigate browser.webNavigation.onCommitted browser.webNavigation.onDOMContentLoaded In each of these I rely on the tab id for various future tab targeting operations. When opening a new tab, the details object passed to each of these callbacks has a non-zero tabId on Chrome, Firefox, and Edge. However, in Safari, the tabId is always zero. To debug, I added one more callback: browser.webNavigation.onCompleted At this point Safari finally has a non-zero tabId in the details param. Needless to say this is causing some consternation with achieving the same outcomes as tab tracking on Chrome, Firefox, and Edge. It's like Safari is treating new tabs as "non tabs" until navigation completes. You can even see it when trying to get the tab by tabId=0: browser.tabs.get(tabId) // tabId=0 here 	.then(tab => { 		// tab is undefined 	}); Seems like this might be a bug. I can't imagine why the behavior is so different from other browsers. Any ideas on how to work around?
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2.7k
Apr ’25
Unable to Override "Link with Highlight" in WKWebView
Hello everyone, I'm working on an app that uses WKWebView. My app uses a custom menu and we disable the default menu by overriding with: WKWebAction.canPerformAction() However, with the new iOS 18.2 release, I am no longer able to override the "Copy Link with Highlight" option that pops up when highlighting a selection as can be seen from the screenshot: Has anyone found a work around/bypass for this? Environment iOS Version: iOS 18.2 Device: iPhone 13 Pro App platform: iOS Xcode version: 16.1 MacOS: 14.5
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1.3k
Sep ’25
safari web extension 在进行direct distribution分发时 在safari setting 中显示“没有权限读取、修改或传输任何网页的内容”
使用direct distribution进行分发时,safari web extension 在safari setting 中显示没有权限读取、修改或传输任何网页的内容。 但是我在看公证日志显示插件是正常的公证的 这导致safari extension 无法使用。 公证日志 https://www.coupert.com/img/2025-04-10/notarization-log.json
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253
Apr ’25
WebView Loading Issue iOS 18.1
Since iOS 18.1 launched as a beta, we've been getting reports from end users on iPhone 15 Pro and iPhone 15 Pro Max specifically. They're reporting that our WebView is unable to load our local HTML content. I'm curious if anyone else has had their app or users run into this issue? So far I've tried installing the most recent XCode Beta 16B5014f and installed an 18.1 emulator, but our app worked fine. It's also working fine on all my real devices, but we don't have a 15 Pro to test on. I'm curious if this is related to the processor on these devices and how they are intended to support Apple's new AI coming in 18.1.
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Jul ’25
Enabling Picture-in-Picture (PiP) in WKWebView
I'm working on a web browser App that's distributed via the App Store. This app renders web pages using WKWebView. Our users are requesting a way for us to allow them to play videos in Picture in Picture. After some investigation, we noticed that in order to allow PiP videos in our browser in the sandboxed environment, we need to add the com.apple.PIPAgent entitlement under the com.apple.security.temporary-exception.mach-lookup.global-name option. We tried to submit our app with this entitlement, but unfortunately, we were rejected: Guideline 2.4.50) - Performance We've determined that one or more temporary entitlement exceptions requested for this app are not appropriate and will not be granted: com.apple.security.temporary-exception.mach-lookup.global-name com.apple.P|PAgent We would like to have access to this entitlement so we can offer PiP to our users. We already created a radar about this as well: FB13814428 Additionally, we have another radar (FB13557716) regarding allowing the usage of a private flag _allowsPictureInPictureMediaPlayback, which would also be required to enable us to use PiP. Is there any way in which we can currently enable PiP? Would opening a TSI help here?
Topic: Safari & Web SubTopic: General Tags:
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JavaScriptCore crashed in iOS 17 and iOS 18
Hello, my application experiences crashes related to JavaScriptCore in iOS 17 and 18. I would like to consult about potential causes, to determine whether it is a bug in JavaScriptCore or an issue with my code implementation. First, the crash stack always includes the call to JSC::MarkedBlock::aboutToMarkSlow(unsigned int). In the iOS 17 version, the crash occurs on this line, typically JSC::MarkedBlock::aboutToMarkSlow(unsigned int) + 88. In iOS 18 and later, the stack crashes atJSC::MarkedBlock::dumpInfoAndCrashForInvalidHandle(WTF::AbstractLocker&, JSC::HeapCell*). I checked the source code of JavaScriptCore for both iOS 17.6 and iOS 18.2 and observed modifications in the implementation of aboutToMarkSlow. My question is under what circumstances could this crash occur? crash.log I have attached a crash log encountered in iOS 18, hoping you can provide more effective information for problem diagnosis, especially since there are specific details worth noting near the crash registers. INVALID HANDLE: MarkedBlock = 0x141158000; heapCell = 0x14115bfa0; type = 0 INVALID HANDLE: found 24 0s at beginning of block INVALID HANDLE: block in another VM: 1, block in another VM: 1; other VM is 0x1324b6000 Moreover, in iOS 18.4, due to the implementation of dumpInfoAndCrashForInvalidHandleV2, the message has changed to: INVALID HANDLE 587: markedBlock=0x303518000; heapCell=0x303518fe0; cellFirst8Bytes=0; subspaceHash=0; contiguousZeros=0; totalzeros=0; blockVM=0x0; actualVM=0x0; isBlockVMValid=0; isBlockInSet=0; isBlockInDir=0; foundInBlockVM=0; INVALID HANDLE 606: markedBlock=0x303518000; heapCell=0x303518fe0; cellFirst8Bytes=0; subspaceHash=0; contiguousZeros=16384; totalZeros=16384; blockVM=0x0; actualVM=0x0; isBlockVMValid=0; isBlockInSet=0; isBlockInDir=0; foundInBlockVM=0; INVALID HANDLE 615: markedBlock=0x303518000; heapCell=0x303518fe0; cellFirst8Bytes=0; subspaceHash=0; contiguousZeros=16384; totalZeros=16384; blockVM=0x0; actualVM=0x0; isBlockVMValid=0; isBlockInSet=1; isBlockInDir=1; foundInBlockVM=0; (Further INVALID HANDLE messages follow the same format) I hope this provides you with more information.
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707
Mar ’25
App’s navigation bar items change background color unexpectedly
iPadOS 26, dark mode Open Safari Search for anything or open a website that has white background Kill Safari Open Safari again I still can reproduce it with Safari on iPadOS 26.0.1 This issue also happens to my app when opening a HTML/JS on WKWebView with white background while using dark mode. I did send a feedback ticket when using iPadOS 26 beta but havent seen any reply. This is my first time sending a feedback so I dont know if Apple would reply or not.
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Oct ’25
"CALayer position contains NaN" Crash in WKWebView on iOS 26 Beta
I’m experiencing a crash in WKWebView on iOS 26 Developer Beta 5 and Beta 6 with the following exception: CALayer position contains NaN: [nan 65] The crash occurs when the following CSS properties are applied to content displayed in WKWebView: -webkit-user-select: none; -webkit-touch-callout: none; This issue happens consistently whenever these styles are set, leading to the crash inside WKWebView. Is this a known bug in the current iOS 26 betas, or is there a recommended workaround?
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Aug ’25
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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549
Mar ’25
Preventing JavaScript from Stopping in Safari When It Goes into the Background
From a mail app or similar, when opening a webpage in Safari as an external browser, JavaScript on the webpage stops running if Safari goes into the background. Is there a way to prevent this from happening? Sample code for the counter: Behavior: Upon returning from the background, the counter continues for about 7-8 seconds but does not progress further. For example, if Safari is kept in the background for about 20 seconds and then brought back, the counter stops at around 7-8 seconds and only resumes counting after returning to the foreground. Expectation: The counter should continue running even if Safari goes into the background.
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Mar ’25
WKWebView occasionally shows white screen and persists until app restart
I am encountering an intermittent issue with WKWebView in my iOS app. The problem occurs infrequently, but when it does, the WKWebView consistently displays a white screen and remains in this state until the app is forcefully terminated and relaunched. To provide more context, here are the key characteristics of the issue: The white screen problem occurs sporadically and is not easily reproducible. The WKWebView remains unresponsive despite attempts to interact with it. Reloading the webpage or navigating to a different URL does not resolve the white screen issue. The problem persists until the app is terminated and relaunched. This issue is specific to the WKWebView; other components of the app function correctly. The WKWebView renders normally, and the main document synchronously loads resources both offline and online without any issues. The bridge and JavaScript execution also work as expected. However, when interacting with the WKWebView, it becomes unresponsive to user clicks, and the web inspector fails to respond. Additionally, asynchronous network requests also do not receive any response. The problem occurs exclusively on HTTPS pages, whereas HTTP pages load without any issues. Other components, such as workers, function correctly. addUserScript injection during WKWebView creation is effective, and evaluateJavaScript during the page loading process works as expected. However, when the document becomes unresponsive, executing evaluateJavaScript only triggers the callback after the WKWebView is destroyed. I have discovered a reliable method to reproduce the white screen issue in WKWebView. This method involves the following steps and conditions: Create a WKWebView instance. Load an HTML page using the loadRequest method(https url request). Before the WKWebView is attached to the UI (not yet visible to the user), call the evaluateJavaScript function. This issue has occurred in almost all iOS versions, including the latest iOS 17.x version.
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Mar ’25
WebAuthn
The passkey authentication dialog appears, and after unlocking with Touch ID, the dialog closes without any notification of success or failure. This issue occurs with high frequency. access to the https://passkeys-demo.appspot.com/ register account and create passkey. logoff access to the url again you can see the passkey dialog unlock device then the dialog disappears nothing happens reload the page proceed 5) to 6) nothing happens or success webauthn.
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1w
What is the recommended way to programmatically apply proxy to WKWebView
Hi Apple engineers! We are making an iOS browser and are planing to deliver a feature that allows enterprise customers to use a MAM key to set a PAC file for proxy. It's designed to support unmanaged device so the MDM based solutions like 'Global HTTP Proxy MDM payload' or 'Per-App VPN' simply don't work. After doing some research we found that with WKWebView, the only framework allowed on iOS for web browsing, there's no API for programmatically setting proxy. The closes API is the WKURLSchemeHandler, but it's for data management not network request interception, in other word it can not be used to handle HTTP/HTTPS request well. When we go from the web-view level to the app level, it seems there's no API to let an app set proxy for itself at an app-level, the closest API is Per-App VPN but as mentioned above, Per-App VPN is only available for managed device so we can't use that as well. Eventually we go to the system level, and try to use Network Extension, but there's still obstacles. It seems Network Extension doesn't directly provide a way to write system proxy. In order to archive that, we may have to use Packet Tunnel Provider in destination IP mode and create a local VPN server to loop back the network traffic and do the proxy stuff in that server. In other word, the custom VPN protocol is 'forward directly without encryption'. This approach looks viable as we see some of the network analysis tools use this approach, but still I'd like to ask is this against App Store Review Guidelines? If the above approach with Network Extension is not against App Store Review Guidelines, I have a further question that, what is the NEProxySettings of NETunnelNetworkSettings for? Is it the proxy which proxies the VPN traffic (in order to hide source IP from VPN provider) or it is the proxy to use after network traffic goes into the virtual private network? If none of the above is considered recommended, what is the recommended way to programmatically set proxy on WKWebView on an unmanaged device (regardless of where the proxy runs, web-view/app/system)?
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1w
SecurityError, show() must be triggered by user activation.
This is a rare occurrence on our site, having only detected 4 instances of it over the past few weeks, where 10s of thousands of transactions have occurred successfully. We only call the following PaymentRequest API onClick from the <apple-pay-button>: async function startApplePay(merchantIdentifier, amount) { ... try { const request = new PaymentRequest([ applePayMethod ], paymentDetails); ... catch (e) { // cancel, just stay here if (e.name === "AbortError") { if (consoleLog) console.log("Payment canceled", e); logServer("INFO", "Payment canceled"); } else { handleError("Error caught: " + e.name + ", " + e.cause + ", " + e.message); } } Where the "handleError" else case is what gets triggered: Error caught: SecurityError, undefined, show() must be triggered by user activation. All 4 instances have been from iPads, but with that small of a sample size, we can't tell whether that's relevant or coincidence. Different iOS versions, but looks like same Safari version. Here are the 4 User Agents we've seen thus far: Mozilla/5.0 (iPad; CPU OS 18_2_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) GSA/352.0.715618234 Mobile/15E148 Safari/604.1 Mozilla/5.0 (iPad; CPU OS 17_6_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) GSA/352.0.715618234 Mobile/15E148 Safari/604.1 Mozilla/5.0 (iPad; CPU OS 18_3_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/133.0.6943.33 Mobile/15E148 Safari/604.1 Mozilla/5.0 (iPad; CPU OS 18_2_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/133.0.6943.33 Mobile/15E148 Safari/604.1
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Feb ’25
iOS 26.1 beta Safari audio input is broken
I'm a web developer of WebRTC based web app for video and audio calls. After updating to iOS 26.1 beta I noticed, that my app can't use microphone anymore. When I'm calling to getUserMedia with audio set to true, Safari returns error "No AVAudioSessionCaptureDevice device". Other WebRTC demo apps also can't access microphone on this firmware. And maybe it's connected somehow, but safari can't detect connected AirPods Pro 2 as an input device. So, this bug brakes any WebRTC app, that uses microphones.
Topic: Safari & Web SubTopic: General Tags:
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Oct ’25