CVE-2025-3889: Tipsandtricks-Hq WordPress Simple PayPal Shopping Cart

Medium severity, CVSS 5.3. EPSS: 0.4% chance of exploitation in the next 30 days.

The WordPress Simple Shopping Cart plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 5.1.3 via the 'process_payment_data' due to missing validation on a user controlled key. This makes it possible for unauthenticated attackers to change the quantity of a product to a negative number, which subtracts the product cost from the total order cost. The attack will only work with Manual Checkout mode, as PayPal and Stripe will not process payments for a negative quantity.

Affected products

• Tipsandtricks-Hq WordPress Simple PayPal Shopping Cart: before 5.1.4 (fixed in 5.1.4)

Published 2025-05-01. Last modified 2026-06-17.