A cross-site scripting (XSS) vulnerability was discovered in the core parser. 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 4.9.10 or lower and TinyMCE 5.4.0 or lower.
This vulnerability has been patched in TinyMCE 4.9.11 and 5.4.1 by improved HTML parsing and sanitization logic.
The workarounds available are:
setup: function(editor) {
editor.on('PreInit', function() {
editor.schema.getSpecialElements()['iframe'] = /</iframe[^>]*>/gi;
});
}
Tiny Technologies would like to thank George Steketee and Chris Davis at Bishop Fox for discovering this vulnerability.
https://www.tiny.cloud/docs/release-notes/release-notes54/#securityfixes
If you have any questions or comments about this advisory:
github.com/tinymce/tinymce
github.com/tinymce/tinymce/commit/2b71c922214d388838d930806207a66c14e80f63
github.com/tinymce/tinymce/commit/696e43658dc9750ec24fdc4650bd2be9653daf5b
github.com/tinymce/tinymce/pull/5843
github.com/tinymce/tinymce/security/advisories/GHSA-vrv8-v4w8-f95h
www.tiny.cloud/docs/release-notes/release-notes54/#securityfixes