CVE-2026-73532

critical

Description

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.

References

https://www.vulncheck.com/advisories/fluent-forms-pro-embedded-malicious-code-via-tampered-plugin-build

https://wpmanageninja.com/security-incident-on-31-july-2026/

https://wordpress.org/plugins/fluentform/

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

Details

Source: Mitre, NVD

Published: 2026-08-13

Updated: 2026-08-14

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

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

Severity: Critical

CVSS v4

Base Score: 9.3

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Severity: Critical

EPSS

EPSS: 0.00463