An XSS issue was discovered in Roundcube Webmail before 1.2.13, 1.3.x before 1.3.16, and 1.4.x before 1.4.10. The attacker can send a plain text e-mail message, with JavaScript in a link reference element that is mishandled by linkrefaddindex in rcubestringreplacer.php.
An issue was discovered in Roundcube Webmail before 1.3.12 and 1.4.x before 1.4.5. There is XSS via a malicious XML attachment because text/xml is among the allowed types for a preview.
Impact Passing HTML containing <option> elements from untrusted sources - even after sanitizing them - to one of jQuery's DOM manipulation methods (i.e. .html(), .append(), and others) may execute untrusted code.
Patches This problem is patched in jQuery 3.5.0.
Workarounds To workaround this issue without upgrading, use DOMPurify with its SAFEFORJQUERY option to sanitize the HTML string before passing it to a jQuery method.
References https://blog.jquery.com/2020/04/10/jquery-3-5-0-released/
For more information If you have any questions or comments about this advisory, search for a relevant issue in the jQuery repo. If you don't find an answer, open a new issue.