VulnerabilityDeferred

CVE-2026-2428

The Fluent Forms Pro Add On Pack plugin for WordPress is vulnerable to Insufficient Verification of Data Authenticity in all versions up to, and including, 6.1.17.

HIGH 7.5EPSS 0.14%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.14%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

The Fluent Forms Pro Add On Pack plugin for WordPress is vulnerable to Insufficient Verification of Data Authenticity in all versions up to, and including, 6.1.17. This is due to the PayPal IPN (Instant Payment Notification) verification being disabled by default (`disable_ipn_verification` defaults to `'yes'` in `PayPalSettings.php`). This makes it possible for unauthenticated attackers to send forged PayPal IPN notifications to the publicly accessible IPN endpoint, marking unpaid form submissions as "paid" and triggering post-payment automation (emails, access grants, digital product delivery).

CVSS 3.1: 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS: 0.14% probability · 4th percentile
CISA KEV: Not listed
Weakness: CWE-345
Source: security@wordfence.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.