Ninja Forms plugin flaw exploited to hack WordPress sites

Hackers are exploiting stored cross-site scripting (XSS) vulnerabilities in two unrelated WordPress plugins, Ninja Forms and WPC Product Bundles for WooCommerce, to install backdoors and create rogue admin accounts. [...]

source https://www.bleepingcomputer.com/news/security/ninja-forms-plugin-flaw-exploited-to-hack-wordpress-sites/