Drupal Improper Neutralization of Input During Web Page Generation (Cross-site Scripting) Vulnerability - CVE-2019-10909
In Symfony before 2.7.51 2.8.x before 2.8.50 3.x before 3.4.26 4.x before 4.1.12 and 4.2.x before 4.2.7 validation messages are not escaped which can lead to XSS when user input is included. This is related to symfony/framework-bundle.