CVE-2026-56831

CVE-2026-56831 · Shopper: Negative discount values accepted and propagated through order calculation pipeline

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

Shopper is a Headless e-commerce Admin Panel. Prior to 2.9.0, the /cpanel/discounts administrative interface accepts negative fixed_amount discount values, persists them in sh_discounts, and passes them through vendor/shopper/cart/src/Discounts/DiscountCalculator.php and vendor/shopper/cart/src/Pipelines/Calculate.php without enforcing a positive-value invariant. Because the calculation subtracts discountTotal from the subtotal, a negative discount increases the resulting order total instead of reducing it. Malformed discount records can therefore cause incorrect pricing and financial data integrity failures, although the advisory does not establish a customer-facing exploitation path. This issue is fixed in version 2.9.0.

CVSS 6.5 · Medium · EPSS 0.4% · Fix available

Published

2026-09-15T17:42:09.495Z

Updated

2026-09-16T14:41:52.114Z

Stack: php

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