An XML external entities (XXE) vulnerability in Jenkins Token Macro Plugin 2.7 and earlier allowed attackers able to control a the content of the input file for the "XML" macro to have Jenkins resolve external entities, resulting in the extraction of secrets from the Jenkins agent, server-side request forgery, or denial-of-service attacks.
https://jenkins.io/security/advisory/2019-06-11/#SECURITY-1399
https://access.redhat.com/errata/RHSA-2019:1851
https://access.redhat.com/errata/RHSA-2019:1636