CVE-2026-65052: Ninja Forms Calculation and Payment Total Tampering via Fail-Open get_calc_value in ListSelect and ListRadio Fields

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-21 · updated 2026-10-24
Weakness: CWE-472

Description

Ninja Forms WordPress plugin version 3.14.8 and prior contains an improper input validation vulnerability that allows unauthenticated attackers to inject arbitrary numeric values into form calculations and payment totals by submitting values that do not match any configured option in ListSelect or ListRadio fields. Attackers can tamper with form submission payloads to the ajax submit endpoint, causing the get_calc_value() method to fail open and return attacker-controlled values, enabling manipulation of payment amounts to zero or arbitrary figures and bypassing admin-configured pricing logic.

Affected products

kstover Ninja Forms – The Contact Form Builder That Grows With You: before 3.14.9 — fixed in 3.14.9

How to fix

Upgrade to a fixed version: kstover Ninja Forms – The Contact Form Builder That Grows With You 3.14.9. Check the vendor advisory for mitigations.

References

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