Mozilla maintains an open ecosystem for add-ons, which gives developers many choices in how they create, use, and deploy their work. This same openness also provides malicious actors more opportunities as well. While Mozilla can identify and block malicious add-ons discovered through tooling, reviews, or user reports, this is not always enough.

Firefox version 115 introduced Quarantined Domains to protect our users' privacy and security when we discover significant security issues presented by malicious actors. This feature allows us to prevent attacks by malicious actors targeting specific domains when we have reason to believe there may be malicious add-ons we have not yet discovered. Users can also control this behavior for each add-on in the Add-on Manager (about:addons) starting with Firefox version 116. We will be further improving the UI for users in future releases.

How can I re-enable the add-ons that are not allowed on sites restricted by Mozilla?

We understand that installing add-ons is a user choice and, as with your security, we also take this matter very seriously. If you are aware of the associated risk and still wish to allow add-ons disallowed on a site by Mozilla, you can do it from the configuration editor (about:config):

1. Type about:config in the address bar and press EnterReturn.
   A warning page may appear. Click Accept the Risk and Continue to go to the about:config page.
2. Search for the extensions.quarantinedDomains.enabled preference.
3. In the type of pref section, select Boolean.
4. Click the + sign next to the pref to create it.
5. Click the Toggle button next to this preference to change its value to false.
6. Restart Firefox.