Jenkins 2.227 and earlier, LTS 2.204.5 and earlier does not properly escape node labels that are shown in the form validation for label expressions on job configuration pages, resulting in a stored XSS vulnerability exploitable by users able to define node labels.
https://jenkins.io/security/advisory/2020-03-25/#SECURITY-1781
http://www.openwall.com/lists/oss-security/2020/03/25/2
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-2161