Drupal's JSON:API and REST/File modules allow file uploads through their HTTP APIs. The modules do not correctly run all file validation, which causes an access bypass vulnerability. An attacker might be able to upload files that bypass the file validation process implemented by modules on the site.

This vulnerability is mitigated by three factors:

The Drupal core Media module allows embedding internal and external media in content fields. In certain circumstances, the filter could allow an unprivileged user to inject HTML into a page when it is accessed by a trusted user with permission to embed media. In some cases, this could lead to cross-site scripting.

This advisory is not covered by Drupal Steward.

The Drupal project uses the pear Archive_Tar library, which has released a security update that impacts Drupal.

The vulnerability is mitigated by the fact that Drupal core's use of the Archive_Tar library is not vulnerable, as it does not permit symlinks.

Exploitation may be possible if contrib or custom code uses the library to extract tar archives (for example .tar, .tar.gz, .bz2, or .tlz) which come from a potentially untrusted source.

This advisory is not covered by Drupal Steward.

Drupal core's sanitization API fails to properly filter cross-site scripting under certain circumstances.

Not all sites and users are affected, but configuration changes to prevent the exploit might be impractical and will vary between sites. Therefore, we recommend all sites update to this release as soon as possible.