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Hi all, I’m seeing a puzzling discrepancy in behavior between NSURLSession (with multipathServiceType = NSURLSessionMultipathServiceTypeInteractive) and WKWebView when the device is connected to a Wi-Fi SSID that has no internet (e.g., a hardware device’s AP). I have the Multipath entitlement properly enabled, and in this scenario: NSURLSession requests automatically fall back to cellular and succeed (no user intervention, fast switch). WKWebView loads fail or stall: the web content does not appear, and it seems like the web view is not using the cellular path even though the system network path becomes satisfied and real Internet reachability is confirmed. Environment: iOS version: (e.g., iOS 18.4) Device: (e.g., iPhone 15 Pro) Multipath entitlement: enabled in the app, using NSURLSessionMultipathServiceTypeInteractive Connected SSID: hardware device Wi-Fi with no external internet Expected fallback: automatic to cellular once the Wi-Fi has no internet, as observed with NSURLSession What I’ve done / observed: NSURLSession using Multipath works as expected:
NSURLSessionConfiguration *cfg = [NSURLSessionConfiguration defaultSessionConfiguration];
cfg.multipathServiceType = NSURLSessionMultipathServiceTypeInteractive;
NSURLSession *session = [NSURLSession sessionWithConfiguration:cfg];
NSURLRequest *req = [NSURLRequest requestWithURL:[NSURL URLWithString:@"https://www.apple.com/library/test/success.html"]];
NSURLSessionDataTask *task = [session dataTaskWithRequest:req completionHandler:^(NSData *data, NSURLResponse *resp, NSError *err) {
NSLog(@"NSURLSession result: %@, error: %@", resp, err);
}];
[task resume];
When connected to the device Wi-Fi (no external internet), the session quietly shifts to cellular and completes successfully. WKWebView fails to load under the same conditions:
[self.webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"https://www.apple.com/library/test/success.html"]]];
The web view either shows a load failure or just hangs, even though lower-level monitoring reports that the network path is satisfied and real Internet connectivity is available. Network path monitoring logic: I use the C API nw_path_monitor to watch for nw_path_status_satisfied. Once satisfied is observed, I perform a true connectivity check using nw_connection (e.g., connecting tohttps://www.apple.com/library/test/success.html) to verify that real Internet traffic can flow over cellular. That check passes, confirming fallback to cellular, but WKWebView still does not load content. Meanwhile, NSURLSession requests in the same condition succeed immediately. Sample logging trace:
[+] nw_path_status_satisfied=1, hasWiFi=1, hasCellular=1
[+] Internet connectivity test: ready (via nw_connection)
[-] WKWebView load failed / stalled
[+] NSURLSession request completed successfully Questions: Why does NSURLSession with the multipath service type seamlessly use cellular when the Wi-Fi has no internet, but WKWebView does not exhibit the same fallback behavior? Is WKWebView not honoring the system’s multipath fallback the same way? Does it use a different networking stack or ignore the multipath entitlement in this scenario? Is there a supported way to force WKWebView to behave like NSURLSession here? For example, can I bridge content through a multipath-enabled NSURLSession and inject it into WKWebView via a custom scheme? Are there any WKWebView configuration flags, preferences, or policies that enable the same automatic interface switching? Are there known limitations or documented differences in how WKWebView handles network interface switching, path satisfaction, or multipath compared to raw NSURLSession? What I’ve ruled out / tried: Verified the Multipath entitlement is included and active. Confirmed network path is “satisfied” and that real Internet reachability succeeds before calling [webView loadRequest:]. Delayed the WKWebView load until after connectivity verification. Observed that NSURLSession requests succeed under identical connectivity conditions. Any insight into internal differences, recommended workarounds, or Apple-recommended patterns for making web content robust in a “Wi-Fi with no internet” + automatic fallback-to-cellular scenario would be greatly appreciated. Thank you!

When setting new entitlements com.apple.developer.networking.carrier-constrained.appcategory and com.apple.developer.networking.carrier-constrained.app-optimized, I have a question about how URLSession should behave. I notice we have a way to specify whether a Network connection should allow ultra-constrained paths via NWParameters allowUltraConstrainedPaths: https://developer.apple.com/documentation/network/nwparameters/allowultraconstrainedpaths There does not appear to be a similar property on URLSessionConfiguration. In an ultra-constrained (eg. satellite) network, should we expect all requests made through an URLSession to fail? Does all network activity when ultra-constrained need to go through a NWConnection or NetworkConnection specifically configured with allowUltraConstrainedPaths, or can URLSession ever be configured to allow ultra-constrained paths?

We are developing an iOS application that is interacting with HTTP APIs that requires us to put a unique UUID (a nonce) as an header on every request (obviously there's more than that, but that's irrilevant to the question here). If the same nonce is sent on two subsequent requests the server returns a 412 error. We should avoid generating this kind of errors as, if repeated, they may be flagged as a malicious activity by the HTTP APIs. We are using URLSession.shared.dataTaskPublisher(for: request) to call the HTTP APIs with request being generated with the unique nonce as an header. On our field tests we are seeing a few cases of the same HTTP request (same nonce) being repeated a few seconds on after the other. Our code has some retry logic only on 401 errors, but that involves a token refresh, and this is not what we are seeing from logs. We were able to replicate this behaviour on our own device using Network Link Conditioner with very bad performance, with XCode's Network inspector attached we can be certain that two HTTP requests with identical headers are actually made automatically, the first request has an "End Reason" of "Retry", the second is "Success" with Status 412. Our questions are: can we disable this behaviour? can we provide a new request for the retry (so that we can update headers)? Thanks, Francesco

I have FileProvider based MacOS application, where user is trying to copy the folder having mix of small and large files. Large files are having size ~ 1.5 GB from FileProvider based drive to locally on Desktop. Since the folder was on cloud and not downloaded the copy action triggered the download. Small files were downloaded successfully however during large file download the URLSession timed out. We are using default timeout for URLSession which is 1 min. I tried to capture logs Console.app where i found FileProvider daemon errors. PFA Solutions tried so far: Increased timeout for URLSession from 5 to 10 mins - configuration.timeoutIntervalForRequest Set timeout for resource - configuration.timeoutIntervalForResource It happens when we have low network bandwidth. Network connectivity is there but the bandwidth is low. Any clue by looking at these errors?

Hi, I am trying to create an App which connects to a Device via Wifi and then has to do some HTTP Requests. Connecting to the Wifi is working properly but when I try to make an HTTP API Call I get the response that the Domain is unavailable (No Internet Connection). I created the App in Flutter on Android everything works perfectly. The packages are all iOS Compatible. But in Safari the URL works so it is probably a permission Issue. I have the Following permissions granted: NSAppTransportSecurity NSBonjourServices NSLocalNetworkUsageDescription I even have Multicast Networking When I test the App I get asked to grant the access to local Network which I am granting. I don´t know what I should do next can somebody help? Feel free to ask for more Information

Starting with iOS 18.3, we are getting infrequent crash reports somehow related to web sockets. Are there any new caveats we should be aware of or is it just a CFNetwork bug? Incident Identifier: 0D4343CE-3089-4514-841D-80CEC353B6B8 Distributor ID: com.apple.AppStore Hardware Model: iPhone16,2 AppStoreTools: 16C7015 AppVariant: 1:iPhone16,2:18 Code Type: ARM-64 (Native) Role: Non UI Parent Process: launchd [1] Date/Time: 2025-03-18 15:42:14.1732 -0400 Launch Time: 2025-03-15 20:38:20.7015 -0400 OS Version: iPhone OS 18.3.1 (22D72) Release Type: User Baseband Version: 2.40.05 Report Version: 104 Exception Type: EXC_BAD_ACCESS (SIGSEGV) Exception Subtype: KERN_INVALID_ADDRESS at 0x0000000000000000 Exception Codes: 0x0000000000000001, 0x0000000000000000 VM Region Info: 0 is not in any region. Bytes before following region: 4373233664 REGION TYPE START - END [ VSIZE] PRT/MAX SHRMOD REGION DETAIL UNUSED SPACE AT START ---> __TEXT 104aa4000-104aa8000 [ 16K] r-x/r-x SM=COW /var/containers/Bundle/Application/EDB47FCF-9E2C-4BE3-A771-F6F84BFCAF31/<redacted> Termination Reason: SIGNAL 11 Segmentation fault: 11 Terminating Process: exc handler [4454] Thread 10 Crashed: 0 CFNetwork 0x0000000193c46aac -[__NSURLSessionWebSocketTask _onqueue_receiveMessageWithCompletionHandler:] + 256 (LocalWebSocketTask.mm:486) 1 CFNetwork 0x0000000193c438b0 -[__NSURLSessionWebSocketTask _onqueue_ioTick] + 636 (LocalWebSocketTask.mm:355) 2 CFNetwork 0x0000000193c46918 __67-[__NSURLSessionWebSocketTask receiveMessageWithCompletionHandler:]_block_invoke + 356 (LocalWebSocketTask.mm:97) 3 libdispatch.dylib 0x000000019a2e9248 _dispatch_call_block_and_release + 32 (init.c:1549) 4 libdispatch.dylib 0x000000019a2eafa8 _dispatch_client_callout + 20 (object.m:576) 5 libdispatch.dylib 0x000000019a2f25cc _dispatch_lane_serial_drain + 768 (queue.c:3934) 6 libdispatch.dylib 0x000000019a2f3158 _dispatch_lane_invoke + 432 (queue.c:4025) 7 libdispatch.dylib 0x000000019a2fe38c _dispatch_root_queue_drain_deferred_wlh + 288 (queue.c:7193) 8 libdispatch.dylib 0x000000019a2fdbd8 _dispatch_workloop_worker_thread + 540 (queue.c:6787) 9 libsystem_pthread.dylib 0x000000021d2e4680 _pthread_wqthread + 288 (pthread.c:2696) 10 libsystem_pthread.dylib 0x000000021d2e2474 start_wqthread + 8 (:-1) Thread 10 crashed with ARM Thread State (64-bit): x0: 0x0000000000000000 x1: 0x0000000000000000 x2: 0x00000000000003f0 x3: 0x0000000000000001 x4: 0x0000000000000010 x5: 0x00000000b04d793d x6: 0x00000000000013c0 x7: 0x0000000000000000 x8: 0x0000000000000378 x9: 0x0000000000000001 x10: 0x00000001fabc6b40 x11: 0x000000000000000f x12: 0x0000000000ddf700 x13: 0x000000012a1bc1c0 x14: 0x00000001fabc9798 x15: 0x00000001fabc9798 x16: 0x000000018faa1c4c x17: 0x000000019a2ea664 x18: 0x0000000000000000 x19: 0x0000000303a83420 x20: 0x0000000000000000 x21: 0x000000012b42d900 x22: 0x00000001fc8000a8 x23: 0x00000001fc8000a8 x24: 0x00000003036913c0 x25: 0x00000003036913c0 x26: 0x0000000000000001 x27: 0x0000000303afc870 x28: 0x0000000000000001 fp: 0x000000016b95a1f0 lr: 0x0000000193c46a04 sp: 0x000000016b95a170 pc: 0x0000000193c46aac cpsr: 0x40001000 esr: 0x92000006 (Data Abort) byte read Translation fault

If I was to build an app that opened a web server at local host on a random port that resolved subdomains for local host at that port, but there was no certificate authority, signed certificate available to provide HTTPS security, would this be in violation of apples ATS policy

Our app connects to the headend to get a IDP login URL for each connection session, for example: “https://myvpn.ocwa.com/+CSCOE+/saml/sp/login?ctx=3627097090&amp;acsamlcap=v2” and then open embedded webview to load the page. (Note: the value of ctx is session token which changes every time). Quite often the webview shows blank white screen. After user cancel the connection and re-connect, the 2nd time webview loads the content successfully. The working case logs shows: didReceiveAuthenticationChallenge is called decidePolicyForNavigationAction is called twice didReceiveAuthenticationChallenge is called decidePolicyForNavigationResponse is called didReceiveAuthenticationChallenge is called But the failure case shows: Filed to terminate process: Error Domain=com.apple.extensionKit.errorDomain Code=18 "(null)" UserInfo={NSUnderlyingError=0x11461c240 {Error Domain=RBSRequestErrorDomain Code=3 "No such process found" UserInfo={NSLocalizedFailureReason=No such process found}}} didReceiveAuthenticationChallenge is called decidePolicyForNavigationAction is called decidePolicyForNavigationResponse is called If we stop calling evaluateJavaScript code to get userAgent, the blank page happens less frequently. Below is the code we put in makeUIView(): func makeUIView(context: Context) -&gt; WKWebView { if let url = URL(string: self.myUrl) { let request = URLRequest(url: url) webview.evaluateJavaScript("navigator.userAgent") { result, error in if let error = error { NSLog("evaluateJavaScript Error: \(error)") } else { let agent = result as! String + " " + self.myUserAgent webview.customUserAgent = agent webview.load(request) } } } return self.webview } Found some posts saying call evaluateJavaScript only after WKWebView has finished loading its content. However, it will block us to send the userAgent info via HTTP request. And I don’t think it is the root cause since the problem still occurs with less frequency. There is no problem to load same web page on Windows desktop and Android devices. The problem only occurs on iOS and macOS which both use WKWebview APIs. Is there a bug in WKWebview? Thanks, Ying

(related post: How to optimize my app for for a carrier-provided satellite network? ) I am trying to implement an app so that it works under a carrier-provided satellite network. The app uses (AS)WebAuthenticationSession for signing in. If the app is entitled to access a satellite network, will (AS)WebAuthenticationSession work as well? How about WKWebView and SFSafariViewController? Is there a way to test(simulate) a ultra-constrained network on a device or a simulator to see the expected behavior? Thanks,

This happens when trying to connect to my development web server. The app works fine when connecting to my production server. The production server has a certificate purchased from a CA. My development web server has a locally generated certificate (from mkcert). I have dragged and dropped the rootCA.pem onto the Simulator, although it doesn't indicate it has been loaded the certificate does appear in the Settings app and is checked to be trusted. I have enabled "App Sandbox" and "Outgoing connections (Client)". I have tested the URL from my local browser which is working fine. What am I missing?

Our application has initiated an NSURLSession data task, and we have received an initiation ID. However, Application not received callback on the subsequent activity: the task has not been requested, has not timed out, and no error callback has been received. [06/17 09:29:40:559][ 0x282a7d8c0] Requested TaskIdentifier 120 2025-06-17 09:29:40.623337 +0530 nsurlsessiond SUBMITTING: com.apple.CFNetwork-cc-166-373-Task .&lt;120&gt;:A71666 default 2025-06-17 09:29:40.631280 +0530 dasd Submitted Activity: com.apple.CFNetwork-cc-166-373-Task .&lt;120&gt;:A71666 at priority 10 default Seen couple of rejection with for CPUUsagePolicy and MemoryPressurePolicy 2025-06-17 09:29:40.989360 +0530 dasd com.apple.CFNetwork-cc-166-373-Task .&lt;120&gt;:A71666:[ {name: CPUUsagePolicy, policyWeight: 5.000, response: {Decision: Must Not Proceed, Score: 0.00, Rationale: [{[Max allowed CPU Usage level]: Required:90.00, Observed:95.00},]}} {name: MemoryPressurePolicy, policyWeight: 5.000, response: {Decision: Must Not Proceed, Score: 0.00, Rationale: [{[memoryPressure]: Required:1.00, Observed:2.00},]}} ], FinalDecision: Must Not Proceed} default 2025-06-17 10:55:22.500277 +0530 dasd com.apple.CFNetwork-cc-166-373-Task .&lt;120&gt;:A71666:[ {name: MemoryPressurePolicy, policyWeight: 5.000, response: {Decision: Must Not Proceed, Score: 0.00, Rationale: [{[memoryPressure]: Required:1.00, Observed:2.00},]}} ], FinalDecision: Must Not Proceed} default And more an hour later then it throws with an error BUT NEVER indicated the same to client 2025-06-17 10:55:27.426549 +0530 WAVE PTX Task .&lt;120&gt; is for &lt;&gt;.&lt;&gt;.&lt;120&gt; default 2025-06-17 10:55:27.776951 +0530 nsurlsessiond Task .&lt;120&gt; summary for task failure {transaction_duration_ms=5147145, response_status=-1, connection=0, reused=1, request_start_ms=0, request_duration_ms=0, response_start_ms=0, response_duration_ms=0, request_bytes=0, response_bytes=0, cache_hit=false} default 2025-06-17 10:55:27.777096 +0530 nsurlsessiond NDSession &lt;714296D7-20F9-4A0A-8C31-71FB67F39A56&gt; Task .&lt;120&gt; for client will be retried after error Error Domain=_nsurlsessiondErrorDomain Code=6 UserInfo={NSErrorFailingURLStringKey=, NSErrorFailingURLKey=, _NSURLErrorRelatedURLSessionTaskErrorKey=, _NSURLErrorFailingURLSessionTaskErrorKey=} - code: 6 default Then It got resumed and says successful but never got any callback on the same to client 2025-06-17 10:55:28.877245 +0530 nsurlsessiond NDSession &lt;714296D7-20F9-4A0A-8C31-71FB67F39A56&gt; Task .&lt;120&gt; resuming default 2025-06-17 10:55:55.225456 +0530 nsurlsessiond Task .&lt;120&gt; received response, status 401 content K default 2025-06-17 10:55:55.250371 +0530 nsurlsessiond Task .&lt;120&gt; finished successfully default Please refer feedback for diagnose logs: https://feedbackassistant.apple.com/feedback/18173303

Question: What is the standard, most reliable way to manage temporary files associated with a URLSessionDownloadTask that has been terminated abnormally due to a network error or other issues? Details Hello, I'm currently developing a feature to download multiple files concurrently on iOS using URLSessionDownloadTask, and I have a question regarding the lifecycle of the temporary files created during this process. As I understand it, URLSessionDownloadTask stores incoming data in a temporary file within the tmp directory, typically with a name like CFNetworkDownload_*.tmp. In my testing, temporary files are managed correctly in the normal scenario. For instance, when I call the cancel() method on an active downloadTask and then release all references to it, the corresponding temporary file is automatically cleaned up from the tmp directory shortly after. However, the problem occurs when a download is interrupted abnormally due to external factors, such as a lost network connection. In this situation, the urlSession(_:task:didCompleteWithError:) delegate method is called, but the associated temporary file is not deleted and remains in the tmp directory. I've observed a particularly interesting behavior related to this. Immediately after the error occurs, if I check my app's storage usage in the iOS Settings app, the data size appears to have decreased momentarily. However, the tmp file has not actually been deleted, and after a short while, the storage usage is recalculated to include the size of this orphaned temporary file. Since my app does not support resuming interrupted downloads, these leftover files become orphaned and unnecessarily consume storage. Therefore, I want to ensure they are all reliably deleted. With this context, I'd like to ask the community: What is the standard, most reliable way to manage temporary files associated with a URLSessionDownloadTask that has been terminated abnormally due to a network error or other issues? I am wondering if there is an official guide or a framework-level API to handle these orphaned files. I would appreciate any advice from those with experience in this area. Thank you.

Hello, I have encountered an issue with an iPhone 15PM with iOS 18.5. The NSHTTPCookieStorage failed to clear cookies, after clearing them, I was still able to retrieve them. However, on the same system NSHTTPCookie *cookie; NSHTTPCookieStorage *storage = [NSHTTPCookieStorage sharedHTTPCookieStorage]; for (cookie in [storage cookies]) { [storage deleteCookie:cookie]; } NSArray *cookies = [[NSHTTPCookieStorage sharedHTTPCookieStorage] cookiesForURL:[[self url] absoluteURL]]; // still able to get cookies,why???

Simulator: iPhone 16 pro (iOS 26) Minimum Deployments: iOS 16.0+, not iOS 17. Here is the demo: import SwiftUI import NetworkExtension struct ContentView: View { private var monitor = NWPathMonitor() var body: some View { VStack { Text("Hello, world!") } .task { let _ = URLSession.shared } } }

Hi all, I’m developing a companion iOS app that connects to a device-created Wi-Fi hotspot to transfer videos or other files WebSocket. The challenge is: once the iPhone connects to this hotspot, it loses internet access because iOS routes all traffic through Wi-Fi. However, I’d like to keep the iPhone’s cellular data active and usable while staying connected to the local hotspot — so the app can access cloud APIs, or the user can continue using other apps that require internet access. I understand that iOS prioritizes Wi-Fi over cellular, but are there any supported workarounds or patterns (e.g., MFi programs, local-only Wi-Fi access, NEHotspotConfiguration behavior, etc.) that : • Using Wi-Fi only for local communication; • cellular to remain active for internet access. Any insights or Apple-recommended best practices would be greatly appreciated — especially any official references regarding MFi Accessory setup or NEHotspotConfiguration behavior in this context. Thanks in !

Hi, i have a crash received in my Firebase Crashlytics. I couldn't figure out the root cause of the issue. Could anyone please help me with it. Crashed: com.apple.CFNetwork.Connection 0 libobjc.A.dylib 0x20b8 objc_retain_x19 + 16 1 CFNetwork 0x47398 HTTP3Fields::appendField(NSString*, NSString*) + 72 2 CFNetwork 0x41250 invocation function for block in HTTP3Stream::_buildRequestHeaders() + 240 3 CoreFoundation 0x249f0 __NSDICTIONARY_IS_CALLING_OUT_TO_A_BLOCK__ + 24 4 CoreFoundation 0x565dc ____NSDictionaryEnumerate_block_invoke_2 + 56 5 CoreFoundation 0x55b10 CFBasicHashApply + 148 6 CoreFoundation 0x8abfc __NSDictionaryEnumerate + 520 7 CFNetwork 0x793d4 HTTP3Stream::scheduleAndOpenWithHandler(CoreSchedulingSet const*, void (__CFHTTPMessage*, NSObject<OS_dispatch_data>*, CFStreamError const*) block_pointer, void (unsigned char) block_pointer) + 1120 8 CFNetwork 0x1665c HTTPProtocol::useNetStreamInfoForRequest(MetaNetStreamInfo*, HTTPRequestMessage const*, unsigned char) + 4044 9 CFNetwork 0x80c80 HTTP3ConnectionCacheEntry::enqueueRequestForProtocol(MetaConnectionCacheClient*, HTTPRequestMessage const*, MetaConnectionOptions) + 2540 10 CFNetwork 0x7fab8 HTTP3ConnectionCacheWrapper::ingestTube(Tube*, bool) + 2924 11 CFNetwork 0x257dc TubeManager::newTubeReady(Tube*, CFStreamError) + 4284 12 CFNetwork 0x57b64 invocation function for block in TubeManager::_onqueue_createNewTube(HTTPConnectionCacheKey*) + 72 13 CFNetwork 0x2fe30 Tube::_onqueue_invokeCB(CFStreamError) + 360 14 CFNetwork 0x2fc20 NWIOConnection::_signalEstablished() + 652 15 CFNetwork 0x4ba1c invocation function for block in NWIOConnection::_handleEvent_ReadyFinish() + 748 16 CFNetwork 0x4b5b0 invocation function for block in Tube::postConnectConfiguration(NSObject<OS_tcp_connection>*, NSObject<OS_nw_parameters>*, void () block_pointer) + 860 17 CFNetwork 0x4b220 BlockHolderVar<std::__1::shared_ptr<NetworkProxy>, bool, CFStreamError>::invoke_normal(std::__1::shared_ptr<NetworkProxy>, bool, CFStreamError) + 64 18 CFNetwork 0x32f2c ProxyConnectionEstablishment::postProxyConnectionConfiguration(__CFAllocator const*, std::__1::shared_ptr<TransportConnection>, NSObject<OS_nw_parameters>*, __CFHTTPMessage*, HTTPConnectionCacheKey*, std::__1::shared_ptr<MetaAuthClient>, SmartBlockWithArgs<std::__1::shared_ptr<NetworkProxy>, bool, CFStreamError>) + 664 19 CFNetwork 0x32bbc Tube::postConnectConfiguration(NSObject<OS_tcp_connection>*, NSObject<OS_nw_parameters>*, void () block_pointer) + 744 20 CFNetwork 0xc19b0 invocation function for block in NWIOConnection::_setupConnectionEvents() + 2360 21 libdispatch.dylib 0x132e8 _dispatch_block_async_invoke2 + 148 22 libdispatch.dylib 0x40d0 _dispatch_client_callout + 20 23 libdispatch.dylib 0xb6d8 _dispatch_lane_serial_drain + 744 24 libdispatch.dylib 0xc214 _dispatch_lane_invoke + 432 25 libdispatch.dylib 0xd670 _dispatch_workloop_invoke + 1732 26 libdispatch.dylib 0x17258 _dispatch_root_queue_drain_deferred_wlh + 288 27 libdispatch.dylib 0x16aa4 _dispatch_workloop_worker_thread + 540 28 libsystem_pthread.dylib 0x4c7c _pthread_wqthread + 288 29 libsystem_pthread.dylib 0x1488 start_wqthread + 8 [Here is the complete crash report.](https://developer.apple.com/forums/content/attachment/58b5bb7d-7c90-4eec-906c-4fb76861d44b)

Hi, I’m trying out my app with Xcode 26, running on an iOS 26 simulator. I'm having issues with URLSessions, it crashes when I set the URLSessionConfiguration to default, and if I don’t use the URLSessionConfiguration, it crashes if I use URLSession.shared. When running in a real device, it doesn't crash, but any network request will hang and time out after a while. Is it a known issue in the latest beta versions?

As stated in the title. I am running the following code. Each time I perform an API call, I create a new instance of URLSession and use a background-configured session to allow background API calls. ` Code being executed: import Foundation // Model definitions struct RandomUserResponse: Codable { let results: [RandomUser] } struct RandomUser: Codable { let name: Name let email: String } struct Name: Codable { let first: String let last: String } // Fetcher class class RandomUserFetcher: NSObject, URLSessionDataDelegate { private var receivedData = Data() private var completion: ((RandomUser?) -&gt; Void)? private var session: URLSession! func fetchRandomUserInBackground(completion: @escaping (RandomUser?) -&gt; Void) { self.completion = completion let configuration = URLSessionConfiguration.background(withIdentifier: "com.example.randomuser.bg") session = URLSession(configuration: configuration, delegate: self, delegateQueue: nil) let url = URL(string: "https://randomuser.me/api/" )! let task = session.dataTask(with: url) task.resume() } // Data received func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) { receivedData.append(data) } // Completion func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: Error?) { defer { self.session.finishTasksAndInvalidate() } guard error == nil else { print("Error: \(error!)") completion?(nil) return } do { let response = try JSONDecoder().decode(RandomUserResponse.self, from: receivedData) completion?(response.results.first) } catch { print("Decoding error: \(error)") completion?(nil) } } }` Called in viewDidLoad, etc.: let fetcher = RandomUserFetcher() fetcher.fetchRandomUserInBackground { user in if let user = user { print("Name: \(user.name.first) \(user.name.last), Email: \(user.email)") } else { print("Failed to fetch random user.") } } In Instruments' Network instrument, I focus on my app's process, use 'Command + 3', and switch to 'List: URLSessionTasks'. Even though didCompleteWithError is called and the API call fully completes, the Duration keeps increasing, and the Success column remains '-' (neither 'Yes' nor 'No'). For non-background URLSessions, the session shows up as 'unnamed session', but for background URLSessions, it appears as 'unnamed background session 1 (XXXXXX-XXXXXX-XXXXX)'. Does this mean the session is not actually being completed? I've checked Debug Memory Graph and confirmed there is no NSURLSession memory leak, but is it possible that the app is somehow still retaining session information internally? I also suspect that Instruments may not be able to fully track background URLSession tasks.

Hello, I have encountered an issue with an iPhone 15PM with iOS 18.5. The NSHTTPCookieStorage failed to clear cookies, but even after clearing them, I was still able to retrieve them. However, on the same system It is normal on iPhone 14PM. I would like to know the specific reason and whether there are any adaptation related issues. Following code: NSHTTPCookie *cookie; NSHTTPCookieStorage *storage = [NSHTTPCookieStorage sharedHTTPCookieStorage]; for (cookie in [storage cookies]) { [storage deleteCookie:cookie]; }

Hello there, Starting from iOS 18.4, support was included for QWAC Validation and QCStatements. Using the official QWAC Validator at: https://eidas.ec.europa.eu/efda/qwac-validation-tool I was able to check that the domain "eidas.ec.europa.eu" has a valid QWAC certificate. However, when trying to obtain the same result using the new API, I do not obtain the same result. Here is my sample playground code: import Foundation import Security import PlaygroundSupport PlaygroundPage.current.needsIndefiniteExecution = true @MainActor class CertificateFetcher: NSObject, URLSessionDelegate { private let url: URL init(url: URL) { self.url = url super.init() } func start() { let session = URLSession(configuration: .ephemeral, delegate: self, delegateQueue: nil) let task = session.dataTask(with: url) { data, response, error in if let error = error { print("Error during request: \(error)") } else { print("Request completed.") } } task.resume() } nonisolated func urlSession(_ session: URLSession, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -&gt; Void) { guard let trust = challenge.protectionSpace.serverTrust else { completionHandler(.cancelAuthenticationChallenge, nil) return } if let certificates = SecTrustCopyCertificateChain(trust) as? [SecCertificate] { self.checkQWAC(certificates: certificates) } let credential = URLCredential(trust: trust) completionHandler(.useCredential, credential) } nonisolated func checkQWAC(certificates: [SecCertificate]) { let policy = SecPolicyCreateSSL(true, nil) var trust: SecTrust? guard SecTrustCreateWithCertificates(certificates as CFArray, policy, &amp;trust) == noErr, let trust else { print("Unable to create SecTrust") return } var error: CFError? guard SecTrustEvaluateWithError(trust, &amp;error) else { print("Trust evaluation failed") return } guard let result = SecTrustCopyResult(trust) as? [String : Any] else { print("No result dictionary") return } let qwacStatus = result[kSecTrustQWACValidation as String] let qcStatements = result[kSecTrustQCStatements as String] print("QWAC Status: \(String(describing: qwacStatus))") print("QC Statements: \(String(describing: qcStatements))") } } let url = URL(string: "https://eidas.ec.europa.eu/")! let fetcher = CertificateFetcher(url: url) fetcher.start() Which prints: QWAC Status: nil QC Statements: nil Request completed. Am I making a mistake while using the Security framework? I would greatly appreciate any help or guidance you can provide.