The CMS installer in Joomla! before 3.7.4 does not verify a user's ownership of a webspace, which allows remote authenticated users to gain control of the target application by leveraging Certificate Transparency logs.

Multiple cross-site scripting (XSS) vulnerabilities in Joomla! 1.5.7 and earlier allow remote authenticated users with certain privileges to inject arbitrary web script or HTML via (1) the title and description parameters to the com_weblinks module and (2) unspecified vectors in the com_content module related to "article submission."