Version Versions of Confluence starting with 4.3.0 before 6.2.1 are affected by this vulnerability.

CVE-2017-9505

Atlassian Confluence starting with 4.3.0 before 6.2.1 did not check if a user had permission to view a page when creating a workbox notification about new comments. An attacker who can login to Confluence could receive workbox notifications, which contain the content of comments, for comments added to a page after they started watching it even if they do not have permission to view the page itself.