Moderately Critical Drupal Core Multiple Vulnerabilities Update

The Media oEmbed iframe route does not properly validate the iframe domain setting, which allows embeds to be displayed in the context of the primary domain. Under certain circumstances, this could lead to cross-site scripting, leaked cookies, or other vulnerabilities.

This advisory is not covered by Drupal Steward.

Solution: 
Install the latest version:

If you are using Drupal 9.4, update to Drupal 9.4.3.
If you are using Drupal 9.3, update to Drupal 9.3.19.

Drupal 7 core does not include the Media module and therefore is not affected.

Source: