A flaw was found in the mercurial plugin in Jenkins. The XML changelog parser is not configured to prevent an XML external entity (XXE) attack allowing an attacker the ability to control an agent process to have Jenkins parse a crafted changelog file that uses external entities for extraction of secrets from the Jenkins controller or server-side request forgery. The highest threat from this vulnerability is to data confidentiality.
A missing permission check in Jenkins Mercurial Plugin 2.11 and earlier allows attackers with Overall/Read permission to obtain a list of names of configured Mercurial installations.