CVE-2026-2428 Fluent Forms Pro Add On Pack <= 6.1.17 - Missing Authorization to Unauthenticated Payment Status modification
Unauthenticated attackers can forge PayPal IPN notifications to mark unpaid form submissions as paid, triggering post-payment automation and granting unauthorized access.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-2428?
CVE-2026-2428 is a high-severity missing authorization vulnerability in techjewel Fluent Forms Pro Add On Pack, published on 27 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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).
Weakness: CWE-345
Which versions are affected by CVE-2026-2428?
How do I fix CVE-2026-2428?
No fix has been published for CVE-2026-2428 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-2428 being exploited?
There is no known exploitation of CVE-2026-2428 in the wild and no public exploit code.
Sources
Also known as GHSA-23j5-87fx-hgc9.