CVE-2026-77470

CVE-2026-77470 · Lychee: Webshop checkout lets the client override the payment `amount` sent to the gateway via malicious crafted POST request

This page contains facts from public vulnerability sources. Check the original advisory before updating.

Lychee is a free, open-source photo-management tool. Prior to 7.7.1, the Supporter or Pro webshop POST /api/v2/Shop/Checkout/Process flow accepts an unrestricted additional_data array and CheckoutService::preparePurchaseParameters() merges it after server-computed purchase parameters. Because later string keys overwrite earlier keys, an unauthenticated buyer can replace amount, currency, returnUrl, cancelUrl, or transactionId before CheckoutService::processPayment() passes the parameters to a non-PayPal Omnipay gateway. An attacker can therefore make a gateway accept a successful payment for an attacker-selected amount and obtain auto-fulfilled goods while underpaying the merchant. The issue requires an enabled webshop, a purchasable item, and an affected Omnipay gateway. This issue is fixed in version 7.7.1.

CVSS 8.3 · High · EPSS 0.5%

Published

2026-10-15T16:36:09.597Z

Updated

2026-10-15T18:30:17.464Z

Check your server →