Quick PayPal Payments <= 6.0.3 - Unauthenticated Payment Amount Manipulation via Payment Form Parameters
- ID
- WPSEC-2026-0943
- Plugin
- Quick PayPal Payments: Payment Button & Form (quick-paypal-payments)
- Affected
- all versions before 6.0.4
- Remediation
- Update to 6.0.4 or later.
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- Weakness
- CWE-472
- Usage
- Plugin Low · Affected versions None seen among sites WPSec scans, 2026-10-14
- Attack surface
- Quick PayPal Payments on WPSec AttackSurface
- Fix released
- Published
Description
The Quick PayPal Payments plugin for WordPress is vulnerable to Payment Amount Manipulation via the payment form submission (the qpp_validate_form AJAX action and the [qpp] shortcode form post) in all versions up to, and including, 6.0.3. This is due to the plugin taking pricing data from the submitted form: price-setting shortcode attributes were posted back as unsigned fields, a posted field skipped validation, a posted form value switched which form's prices applied, loosely compared values matched a fixed price option, a quantity of zero was accepted on forms without a quantity field, and a crafted item amount lowered a subscription's per-period price. This makes it possible for unauthenticated attackers to pay less than the configured price and have the payment recorded as paid; since 5.7.51 the forged price is also stored as the amount the IPN check expects.
References
- https://wpsec.com/vuln/WPSEC-2026-0943/
- https://plugins.svn.wordpress.org/quick-paypal-payments/tags/6.0.4/
- https://wordpress.org/plugins/quick-paypal-payments/
Published by WPSec. Provided as is, without warranty. Corrections: contact us.
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