ABC Notation <= 6.1.3 - Authenticated (Contributor+) Arbitrary File Read

The ABC Notation plugin for WordPress is vulnerable to Path Traversal in all versions up to, and including, 6.1.3 via the 'file' attribute of the 'abcjs' shortcode. This makes it possible for authenticated attackers, with Contributor-level access and above, to read the contents of arbitrary files on the server, which can contain sensitive information.