A security vulnerability impacts the Ninja Tables Pro WordPress plugin, specifically version 5.2.11. A tampered, malicious version of this plugin was distributed through a decommissioned (no longer active) update server, so sites that installed this specific plugin version may have unknowingly added harmful code to their websites.
The compromised plugin includes hidden malicious functionality that creates several serious risks: it sets up a secret remote access point for attackers, drops persistent harmful files in your site's mu-plugins and uploads folders, creates a hidden administrator account with no required password that grants full access to your site's backend, and sets up automated scheduled tasks that keep the harmful code active even if you later delete the Ninja Tables plugin from your site.
Source: NVD (National Vulnerability Database) — https://nvd.nist.gov/vuln/detail/CVE-2026-73533
