---
id: CVE-2026-56831
title: Shopper is a Headless e-commerce Admin Panel
summary: >-
  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/Di…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N'
cwe:
  - CWE-20
vendor: shopperlabs
product: shopper
affected:
  - shopper < 2.9.0
patched:
  - shopper/framework 2.9.0
published: '2026-09-15'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T15:17:38.200'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-56831'
references:
  - url: >-
      https://github.com/shopperlabs/shopper/commit/967e616281ded1a0050d9102858ecd7dd7f66a41
    label: security-advisories@github.com
  - url: 'https://github.com/shopperlabs/shopper/pull/528'
    label: security-advisories@github.com
  - url: 'https://github.com/shopperlabs/shopper/releases/tag/v2.9.0'
    label: security-advisories@github.com
  - url: >-
      https://github.com/shopperlabs/shopper/security/advisories/GHSA-5vf4-452p-jjhf
    label: security-advisories@github.com
  - url: >-
      https://github.com/shopperlabs/shopper/security/advisories/GHSA-5vf4-452p-jjhf
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/advisories/GHSA-5vf4-452p-jjhf'
tags:
  - nvd
  - cve.org
  - exploit-available
  - ghsa
  - composer
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-16T14:41:46.439666Z'
aliases:
  - GHSA-5vf4-452p-jjhf
ecosystem: composer
ingestedAt: '2026-09-12T00:03:49.069Z'
epss: 0.00435
epssPercentile: 0.35216
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-56831)

Affected packages:

- `shopper/framework < 2.9.0`

Patched in:

- `shopper/framework 2.9.0`

Source: https://github.com/advisories/GHSA-5vf4-452p-jjhf