The Webform module uses the CKEditor, library for WYSIWYG editing. CKEditor has released a security update that impacts Webform.

An attacker that can create or edit content (even without access to CKEditor themselves) may be able to exploit one or more Cross-Site Scripting (XSS) vulnerabilities to target users with access to the WYSIWYG CKEditor, including site admins with privileged access.

For more information, see CKEditor's announcement of the release.