From MozillaZine Knowledge Base



While Firefox’s extension system is arguably the browser’s most powerful feature, it can also be a vector for malware. With Firefox 2.0, specific extensions can be blacklisted from a central server (by default, This preference specifies a URL that the user can visit to learn more about the extension blocklist.

Possible values and their effects

Any valid URL may be specified. (Default:

First checked in

2006-03-08 by Robert Strong

Has an effect in

  • Mozilla Firefox (trunk builds after 2006-03-08; 2.0)

Related bugs

Related preferences

External links