When the priorities of your company shift daily, Scrum is not your ally. Scrum helps keeping your development team safe from the crazy whims of the outside world. Did you not add it in sprint planning? Then please wait until the next sprint if possible. If not possible, then we first check if it does not endanger the sprint goal before adding it. And if we do add it, we most likely will also remove something else. If stakeholders are affected, we can immediately inform them.