It was possible to execute a ReDoS-type attack inside CKEditor 4 before 4.16 by persuading a victim to paste crafted URL-like text into the editor, and then press Enter or Space (in the Autolink plugin).
{ "ubuntu_priority": "medium" }
{ "availability": "No subscription required", "ubuntu_priority": "medium", "binaries": [ { "binary_version": "4.16.2+dfsg-1", "binary_name": "ckeditor" } ] }