﻿id,summary,reporter,owner,description,type,status,priority,milestone,component,version,severity,resolution,keywords,cc,focuses,prnumber 40787,REST API: Attempts to output headers without confirming headers have not been sent,kraftbj,jnylen0,"The `rest_handle_deprecated_function` and `rest_handle_deprecated_argument` functions fire `header()` without confirming if headers have already been sent or not. This can result in PHP warnings, which depending on the site's settings, will output into the REST API response, which breaks JSON. {{{ Error: Warning: Cannot modify header information - headers already sent by (output started at /public_html//wp-includes/functions.php:3720) in /public_html/wp-includes/rest-api.php on line 492 }}}",defect (bug),closed,normal,4.8,REST API,,normal,fixed,has-patch dev-feedback,,rest-api,