The blocklist lists browser extensions, plugins and other components that are blocked automatically by Firefox either directly or sometimes in the case of plugins, by setting them to "ask to activate".
Mozilla has added all versions of Adobe Flash up to the most recent version 188.8.131.52 to the Firefox blocklist.
Security researchers have discovered vulnerabilities in recent versions of Adobe Flash that have not been patched yet by Adobe but are exploited in the wild.
In particular, several exploit kits are already making use of it to serve crypto-ransomware to systems running Adobe Flash.
In an effort to protect Firefox users from harm on the Internet, Mozilla has added the current version of Adobe Flash and all previous versions to the browser's blocklist.
If selected, Flash contents will be loaded and can be used just like before.
The blocklist update may not have been deployed on all Firefox machines.You may request a manual update of the blocklist at any time using the method below: The blocklist should update if updates are available.The difference between "ask to activate" and "never activate" is that Flash is not blocked completely in the former state which means that Flash contents can still be accessed in the browser.While that requires an extra click, it ensures that code on websites cannot exploit the vulnerability automatically without user action.Options to switch the state are not available due to Flash being on the browser's blocklist.Firefox displays a warning in the browser whenever Flash contents are embedded on a web page: The prompt displays options to allow the plugin on the page.