Contao is an Open Source CMS. From version 4.0.0 to before 4.13.57, before 5.3.42, and before 5.6.5, back end users with precise control over the contents of template closures can execute arbitrary PHP functions that do not have required parameters. This issue has been patched in versions 4.13.57, 5.3.42, and 5.6.5. A workaround for this issue involves manually patching the Contao\Template::once() method.
Contao is an Open Source CMS. From version 4.0.0 to before 4.13.57, before 5.3.42, and before 5.6.5, it is possible to inject code into the template output that will be executed in the browser in the front end and back end. This issue has been patched in versions 4.13.57, 5.3.42, and 5.6.5. A workaround for this issue involves not using the affected templates or patch them manually.
Contao is an Open Source CMS. In versions starting from 4.9.14 and prior to 4.13.56, 5.3.38, and 5.6.1, protected content elements that are rendered as fragments are indexed and become publicly available in the front end search. This issue has been patched in versions 4.13.56, 5.3.38, and 5.6.1. A workaround involves disabling the front end search.
Contao is an Open Source CMS. Users can upload SVG files with malicious code, which is then executed in the back end and/or front end. This vulnerability is fixed in Contao 4.13.54, 5.3.30, or 5.5.6.
Contao before 5.5.6 allows XSS via an SVG document. This affects (in contao/core-bundle in Composer) 4.x before 4.13.54, 5.0.x through 5.3.x before 5.3.30, and 5.4.x and 5.5..x before 5.5.6.