Affected versions of Atlassian Jira Server and Data Center allow remote attackers with administrator privileges to execute arbitrary code via a Remote Code Execution (RCE) vulnerability in the Email Templates feature. This issue bypasses the fix of https://jira.atlassian.com/browse/JSDSERVER-8665. The affected versions are before version 8.13.15 and from version 8.14.0 before 8.20.3.