Wordpress : Security Vulnerabilities, CVEs, Published In December 2019 CVSS score >= 1

WordPress users with lower privileges (like contributors) can inject JavaScript code in the block editor using a specific payload, which is executed within the dashboard. This can lead to XSS if an admin opens the post in the editor. Execution of this attack does require an authenticated user. This has been patched in WordPress 5.3.1, along with all the previous WordPress versions from 3.7 to 5.3 via a minor release. Automatic updates are enabled by default for minor releases and we strongly recommend that you keep them enabled.

In WordPress before 5.3.1, authenticated users with lower privileges (like contributors) can inject JavaScript code in the block editor, which is executed within the dashboard. It can lead to an admin opening the affected post in the editor leading to XSS.

wp_kses_bad_protocol in wp-includes/kses.php in WordPress before 5.3.1 mishandles the HTML5 colon named entity, allowing attackers to bypass input sanitization, as demonstrated by the javascript: substring.

In wp-includes/formatting.php in WordPress 3.7 to 5.3.0, the function wp_targeted_link_rel() can be used in a particular way to result in a stored cross-site scripting (XSS) vulnerability. This has been patched in WordPress 5.3.1, along with all the previous WordPress versions from 3.7 to 5.3 via a minor release.

In in wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php in WordPress 3.7 to 5.3.0, authenticated users who do not have the rights to publish a post are able to mark posts as sticky or unsticky via the REST API. For example, the contributor role does not have such rights, but this allowed them to bypass that. This has been patched in WordPress 5.3.1, along with all the previous WordPress versions from 3.7 to 5.3 via a minor release.