Affected versions of Jira Server & Data Center allow a remote attacker with limited (non-admin) privileges to view a Jira instance's Support Entitlement Number (SEN) via an Information Disclosure vulnerability in the HTTP Response headers. The affected versions are before version 7.13.18, from version 8.0.0 before 8.5.9, and from version 8.6.0 before 8.12.1.