Readest is an open-source e-book reader built on Tauri. In versions prior to 0.11.16, EPUB chapter HTML is sanitized with DOMPurify using a configuration that forbade only the <script> tag (FORBIDTAGS: ['script']) in apps/readest-app/src/services/transformers/sanitizer.ts. DOMPurify does not parse the contents of the srcdoc attribute on <iframe> elements, treating it as an opaque string attribute, so an attacker who can get an <iframe> element to survive sanitization can embed a complete HTML document containing a <script> tag inside srcdoc and have it execute when the browser renders the iframe. The content iframe is configured with sandbox="allow-same-origin allow-scripts", so script executing inside it shares the parent origin and can reach parent.parent.TAURIINTERNALS.invoke(...), giving access to every Tauri IPC command the application is permitted to use, which escalates to arbitrary code execution. The payload can be made invisible (zero-size, transparent iframe) so the reader sees only normal book text. Version 0.11.16 hardened the sanitizer configuration by adding 'iframe', 'object' and 'embed' to FORBIDTAGS and adding 'srcdoc' to FORBIDATTR.