The Yumpu E-Paper publishing plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'YUMPU' shortcode in all versions up to, and including, 3.0.8 due to insufficient input sanitization and output escaping on user supplied attributes. 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.

The Yumpu ePaper publishing plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the ajax_handler function in all versions up to, and including, 2.0.24. This makes it possible for authenticated attackers, with subscriber-level access and above, to upload PDF files and publish them, as well as modify the API key.