Jenkins: Stored XSS vulnerability in node offline cause description

Jenkins 2.483 through 2.567 (both inclusive), LTS 2.492.1 through 2.555.2 (both inclusive) does not escape the user-provided description of a generic offline cause that could be set through the POST config.xml API, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers with Agent/Configure permission.