CVE-2026-73532

Fluent Forms Pro 6.2.7 contains an embedded malicious code vulnerability introduced via a tampered plugin build served through a decommissioned update server. The tampered build introduced a rogue PHP file (libs/class-license-sync.php), loaded via a require_once directive added to fluentformpro.php, that established a backdoor REST API endpoint, dropped persistent PHP files in mu-plugins and uploads directories, installed a passwordless administrator account, and registered scheduled tasks that survived plugin removal.

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

• https://patchstack.com/database/wordpress/plugin/fluentformpro/vulnerability/wordpress-fluent-forms-pro-add-on-pack-plugin-6-2-7-6-2-7-remote-code-execution-vulnerability
• https://wordpress.org/plugins/fluentform/
• https://wpmanageninja.com/security-incident-on-31-july-2026/
• https://www.vulncheck.com/advisories/fluent-forms-pro-embedded-malicious-code-via-tampered-plugin-build