Contao is a powerful open source CMS that allows you to create professional websites and scalable web applications. In versions of Contao prior to 4.13.3 it is possible to inject code into the canonical tag. As a workaround users may disable canonical tags in the root page settings.
Cross-site Scripting (XSS) in GitHub repository contao/contao prior to 4.13.3. Attacker can execute Malicious JS in Application :)
Contao >=4.0.0 allows backend XSS via HTML attributes to an HTML field. Fixed in 4.4.56, 4.9.18, 4.11.7.
Contao 4.5.x through 4.9.x before 4.9.16, and 4.10.x through 4.11.x before 4.11.5, allows XSS. It is possible to inject code into the tl_log table that will be executed in the browser when the system log is called in the back end.
Contao before 4.4.52, 4.9.x before 4.9.6, and 4.10.x before 4.10.1 have Improper Input Validation. It is possible to inject insert tags in front end forms which will be replaced when the page is rendered.
Contao before 4.5.7 has XSS in the system log.
contao prior to 2.11.4 has a sql injection vulnerability
Contao 4.0 through 4.8.5 has Insecure Permissions. Back end users can manipulate the details view URL to show pages and articles that have not been enabled for them.
Contao 4.0 through 4.8.5 allows PHP local file inclusion. A back end user with access to the form generator can upload arbitrary files and execute them on the server.
Contao 4.8.4 and 4.8.5 has Improper Encoding or Escaping of Output. It is possible to inject insert tags into the login module which will be replaced when the page is rendered.
Contao 4.x allows SQL Injection. Fixed in Contao 4.4.39 and Contao 4.7.5.