WordPress has just released a new update version 4.5.3 which is mainly a security release fixing a major security issue present in all the previous wordpress versions. It is strongly recommends to update your sites immediately to the latest version.
This vulnerability allows an attacker to gain access to password protected posts in wordpress. This vulnerability is high in case of wordpress installations with open registrations.
Wordfence, a popular wordpress security plugin disclosed this vulnerability to wordpress on 3rd May