[iOS 26 Beta] event.target.value is always empty — only from specific script domains

Hey everyone,

After installing iOS 26 beta, I started noticing unexpected behavior in our input event handlers.

Specifically, when users type into an <input> field, event.target.value is always an empty string — but only when the JS file is loaded from a specific domain (e.g., t1.daumcdn.net). The exact same code works perfectly when hosted on other domains like t2.daumcdn.net or search1.daumcdn.net.

👉 I created a demo here: 🔗 https://codepen.io/bzasklcu-the-sans/pen/rNXogxL

The scripts loaded from each domain are 100% identical (apart from the top-level selector). Before iOS 26 beta, this worked fine.

I suspect this is related to ITP or some new cross-origin behavior in Safari, but I’d love to know if anyone else is running into this — or if someone knows a workaround.

Thanks!