Medium · published May 12, 2021
CVSS calls it medium at 5.3. It sits in the 99.9th percentile for exploit probability.
Affected versions of Atlassian Jira Server and Data Center allow an unauthenticated user to enumerate users via an Information Disclosure vulnerability in the QueryComponentRendererValue!Default.jspa endpoint. The affected versions are before version 8.5.13, from version 8.6.0 before 8.13.5, and from version 8.14.0 before 8.15.1.