GHSA-c78w-2gw7-gjv3

XSS in TinyMCE

### Impact A cross-site scripting (XSS) vulnerability was discovered in: the core parser and `media` plugin. The vulnerability allowed arbitrary JavaScript execution when inserting a specially crafted piece of content into the editor via the clipboard or APIs. This impacts all users who are using TinyMCE 4.9.9 or lower and TinyMCE 5.2.1 or lower. ### Patches This vulnerability has been patched in TinyMCE 4.9.10 and 5.2.2 by improved HTML parsing and sanitization logic. ### Workarounds The workarounds available are: - disable the media plugin and manually sanitize CDATA content (see below) or - upgrade to either TinyMCE 4.9.10 or TinyMCE 5.2.2 #### Example: Manually strip CDATA elements ```js setup: function(editor) { editor.on('PreInit', function() { editor.parser.addNodeFilter('#cdata', function(nodes) { for (var i = 0; i < nodes.length; i++) { nodes[i].remove(); } }); }); } ``` ### Acknowledgements Tiny Technologies would like to thank Michał Bentkowski and [intivesec](https://github.com/intivesec) for discovering these vulnerabilities. ### References https://www.tiny.cloud/docs/release-notes/release-notes522/#securityfixes ### For more information If you have any questions or comments about this advisory: * Open an issue in the [TinyMCE repo](https://github.com/tinymce/tinymce/issues) * Email us at [infosec@tiny.cloud](mailto:infosec@tiny.cloud)