An issue was discovered in Joomla! Core before 3.8.8. Under specific circumstances (a redirect issued with a URI containing a username and password when the Location: header cannot be used), a lack of escaping the user-info component of the URI could result in an XSS vulnerability.
In Joomla! before 3.8.4, the lack of type casting of a variable in a SQL statement leads to a SQL injection vulnerability in the Hathor postinstall message.
In Joomla! before 3.8.4, inadequate input filtering in com_fields leads to an XSS vulnerability in multiple field types, i.e., list, radio, and checkbox
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.
The mailSend function in the isMail transport in PHPMailer before 5.2.18 might allow remote attackers to pass extra parameters to the mail command and consequently execute arbitrary code via a \" (backslash double quote) in a crafted Sender property.