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.
- Score
- CVSS 3.1 9.8 Critical
- Status
- Deferred - disclosure@vulncheck.com
- Published
- 2026-08-13
- Last modified
- 2026-08-14
- Weaknesses
- CWE-506
Affected products
References
- https://patchstack.com/database/wordpress/plugin/fluentformpro/vulnerability/wordpress-fluent-forms-pro-add-on-pack-plu…
- 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
