Presence of read restricted topics may be leaked if tagged with a tag that is visible to all users
Package
Discourse
(Discourse)
Affected versions
stable <= 3.0.0; beta <= 3.1.0.beta1; tests-passed <= 3.1.0.beta1
Patched versions
stable > 3.0.0; beta > 3.1.0.beta1; tests-passed > 3.1.0.beta1
Impact
Currently, the count of topics displayed for a tag is a count of all regular topics regardless of whether the topic is in a read restricted category or not. As a result, any users can technically poll a sensitive tag to determine if a new topic is created in a category which the user does not have excess to.
Patches
In the patched versions, the count of topics displayed for a tag defaults to only counting regular topics which are not in read restricted categories. Staff users will continue to see a count of all topics regardless of the topic's category read restrictions.