CNAME Uncloaking Tests

Test instructions: Visit this page on and confirm that the status of a CNAME cloaked network request is consistent with the following expected behavior:

Initial Setup

First, add the following line to brave://adblock:


A default Brave installation should then cause the request to be blocked.

Disabling conditions

Any of the following conditions should cause the request to be allowed. Network analysis should also reveal that no additional DNS queries are made alongside the request.

  • Shields down
  • #brave-adblock-cname-uncloaking feature flag disabled in brave://flags
  • Tor session
  • Proxy/VPN WebExtension installed and active