Trix is a rich text editor. The Trix editor, versions prior to 2.1.1, is vulnerable to arbitrary code execution when copying and pasting content from the web or other documents with markup into the editor. The vulnerability stems from improper sanitization of pasted content, allowing an attacker to embed malicious scripts which are executed within the context of the application. Users should upgrade to Trix editor version 2.1.1 or later, which incorporates proper sanitization of input from copied content.