Most of the single-SWF movies people think about when they think of Flash entirely fit within the current Web sandbox. Flash does have it's own bizzaro-world i

Most of the single-SWF movies people think about when they think of Flash entirely fit within the current Web sandbox. Flash does have it's own bizzaro-world idea of CORS, though, which can cause issues with web services not aware of it. Adobe also went through a lot of work in AS3 to support "opaque" SWF content, i.e. being able to hotlink other domains' movies in the same way browsers can hotlink images. It is a concept that makes absolutely no sense in a post-Spectre world. But a lot of movies just outright don't need those features - it's definitely not a "rewrite all Flash Player content" situation.