In Joomla! before 3.8.0, inadequate escaping in the LDAP authentication plugin can result in a disclosure of a username and password.

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.

In Joomla! before 3.7.4, inadequate filtering of potentially malicious HTML tags leads to XSS vulnerabilities in various components.

In Joomla! 1.6.0 through 3.6.5 (fixed in 3.7.0), inadequate filtering of form contents allows overwriting the author of an article.

In Joomla! 1.5.0 through 3.6.5 (fixed in 3.7.0), mail sent using the JMail API leaked the used PHPMailer version in the mail headers.

In Joomla! 1.5.0 through 3.6.5 (fixed in 3.7.0), inadequate filtering of specific HTML attributes leads to XSS vulnerabilities in various components.

Joomla! 1.5.x, 2.x, and 3.x before 3.4.6 allow remote attackers to conduct PHP object injection attacks and execute arbitrary PHP code via the HTTP User-Agent header, as exploited in the wild in December 2015.

Cross-site scripting (XSS) vulnerability in the ja_purity template for Joomla! 1.5.26 and earlier allows remote attackers to inject arbitrary web script or HTML via the Mod* cookie parameter to html/modules.php.

Joomla! 1.5.x before 1.5.26 does not properly check permissions, which allows attackers to obtain sensitive "administrative back end information" via unknown vectors. NOTE: this might be a duplicate of CVE-2012-1611.

Joomla! 1.5.x before 1.5.26 has unspecified impact and attack vectors related to "insufficient randomness" and a "password reset vulnerability."