WKWebView customUserAgent replaces system User-Agent with NetworkingExtension identifier on iOS 26.4
Reproduction Steps:a. Create a WKWebView instance and set a custom string to customUserAgent.b. Load any web page (e.g., https://example.com).c. Check the User-Agent field in the request headers via packet capture tools or Web Inspector. Expected Result:The custom User-Agent should be appended to the default system identifier (Mozilla/5.0 (iPhone; CPU iPhone OS 18_7 like Mac OS X) AppleWebKit/605.1.15...), instead of being completely overwritten. Actual Result:The User-Agent is fully replaced with: NetworkingExtension/8624.1.16.10.6 Network/5812.102.3 iOS/26.4, and all basic system identifiers are missing. Additional Information: Device: iPhone 16 Pro Max iOS Version: 26.4 (Build 20T5127) WKWebView setup: Directly set using the customUserAgent property Network Extension features are not used in the project, but the NetworkingExtension identifier still appears in the User-Agent
It looks like you’re trying to report a bug. If so, the best place to do that is in Feedback Assistant. See Bug Reporting: How and Why? for lots of hints and tips for that process.
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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"
It looks like you’re trying to report a bug. If so, the best place to do that is in Feedback Assistant. See Bug Reporting: How and Why? for lots of hints and tips for that process.
Please post your bug number, just for the record.
Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"
I found the problem. The UserAgent contains Chinese characters, so it was parsed as:User-Agent: NetworkingExtension/8624.1.16.10.6 Network/5812.102.3 iOS/26.4This worked fine in previous iOS versions. Can this issue be fixed?