Wordpress, so nicht!
Current versions of WordPress are vulnerable to a stored XSS. An unauthenticated attacker can inject JavaScript in WordPress comments. The script is triggered when the comment is viewed.
If triggered by a logged-in administrator, under default settings the attacker can leverage the vulnerability to execute arbitrary code on the server via the plugin and theme editors.
Alternatively the attacker could change the administrator’s password, create new administrator accounts, or do whatever else the currently logged-in administrator can do on the target system.
Money quote:
WordPress has refused all communication attempts about our ongoing security vulnerability cases since November 2014. We have tried to reach them by email, via the national authority (CERT-FI), and via HackerOne. No answer of any kind has been received since November 20, 2014.
WTF?!