Social Flexible Group is an Open Social extension that allows users to create groups with many different configurations.

In specific uncommon scenarios, where a platform doesn't have any flexible groups with the "Group members only (secret)" visibility, community groups are visible to anonymous users on the /all-groups page. No other group information is revealed since group access is not affected by this issue.

This vulnerability is mitigated by creating a Flexible Group with visibility "Group members only (secret)".