I had the same crash with same crashlog. In my case I used WKWebView to display PDF document. Crash used to occur when you long press to call actions menu anywhere in the area without text. If you long press on text, actions menu was displayed without crash. It was on iOS 26 beta 5, but now on iOS 26 beta 7 I can't reproduce crash in such scenario. Looks like it was fixed, but can't say for sure, since I didn't find mentions of such problem in release notes.