The MessageBundleResource resource in Jira Server and Data Center before version 7.13.4, from 8.5.0 before 8.5.5, from 8.8.0 before 8.8.2, and from 8.9.0 before 8.9.1 allows remote attackers to impact the application's availability via an Denial of Service (DoS) vulnerability.
The email client in Jira Server and Data Center before version 7.13.16, from 8.5.0 before 8.5.7, from 8.8.0 before 8.8.2, and from 8.9.0 before 8.9.1 allows remote attackers to access outgoing emails between a Jira instance and the SMTP server via man-in-the-middle (MITM) vulnerability.