CKEditor 4.x before 4.11.0 allows user-assisted XSS involving a source-mode paste.
{ "binaries": [ { "binary_version": "4.5.7+dfsg-2ubuntu0.16.04.1~esm2", "binary_name": "ckeditor" } ] }
{ "binaries": [ { "binary_version": "4.5.7+dfsg-2ubuntu0.18.04.1+esm1", "binary_name": "ckeditor" } ] }