Firefox 57, scheduled for release on November 14, will ship with a new protective measure that will prevent accessibility apps from accessing the web browser’s data. Accessibility is a term used to describe the design of products for people with disabilities. Firefox’s accessibility features allow specialized accessibility apps to connect to the browser and interpret browsing data for persons with disabilities. For example, screen readers use Firefox’s accessibility support to read content from an active web page, menus, buttons, preferences, browser history, or others.
Source: Upcoming Firefox 57 Gets New Protection Against Apps That Snoop on Users