---
id: CVE-2026-77470
title: 'Lychee is a free, open-source photo-management tool'
summary: >-
  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() merg…
severity: high
cvss: 8.3
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N'
cwe:
  - CWE-20
  - CWE-472
  - CWE-915
vendor: LycheeOrg
product: Lychee
affected:
  - Lychee < 7.7.1
published: '2026-10-15'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T19:17:43.390'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-77470'
references:
  - url: >-
      https://github.com/LycheeOrg/Lychee/commit/24e6e11f1da131ed20b192d7d7b7ca9084451a2f
    label: security-advisories@github.com
  - url: 'https://github.com/LycheeOrg/Lychee/pull/4514'
    label: security-advisories@github.com
  - url: 'https://github.com/LycheeOrg/Lychee/releases/tag/v7.7.1'
    label: security-advisories@github.com
  - url: >-
      https://github.com/LycheeOrg/Lychee/security/advisories/GHSA-476v-jr53-8rxc
    label: security-advisories@github.com
  - url: >-
      https://github.com/LycheeOrg/Lychee/security/advisories/GHSA-476v-jr53-8rxc
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-15T18:29:45.817503Z'
cvssSource: cna
ingestedAt: '2026-10-15T17:18:20.101Z'
---

## Overview

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.

## Remediation

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