The mw_editPost function in wp-includes/class-wp-xmlrpc-server.php in the XMLRPC subsystem in WordPress before 4.3.1 allows remote authenticated users to bypass intended access restrictions, and arrange for a private post to be published and sticky, via unspecified vectors.
https://wpvulndb.com/vulnerabilities/8188
https://wordpress.org/news/2015/09/wordpress-4-3-1/
https://security-tracker.debian.org/tracker/CVE-2015-5715
https://github.com/WordPress/WordPress/commit/9c57f3a4291f2311ae05f22c10eedeb0f69337ab
https://codex.wordpress.org/Version_4.3.1
http://www.securitytracker.com/id/1033979
http://www.securityfocus.com/bid/76748