Element X iOS is a Matrix iOS Client provided by Element. Element X iOS before version 26.05.0 fails to check the URL allowlist when parsing io.element.call://. If an attacker is able to trick the user into opening a maliciously crafted io.element.call:// URL, they are able to load an attacker-controlled origin inside the call screen's WKWebView which will be granted device microphone and camera permissions (provided the user has previously granted these permissions to Element X iOS). This issue has been patched in version 26.05.0.