The WP Last Modified Info plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘template’ attribute of the lmt-post-modified-info shortcode in all versions up to, and including, 1.9.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
https://wordpress.org/plugins/wp-last-modified-info/#developers
https://plugins.trac.wordpress.org/changeset/3137253/#file23