{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "7.7.1"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "24e6e11f1da131ed20b192d7d7b7ca9084451a2f"
            }
          ],
          "repo": "https://github.com/lycheeorg/lychee",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-476v-jr53-8rxc"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-20",
      "CWE-472",
      "CWE-915"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77470.json"
  },
  "details": "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.",
  "id": "CVE-2026-77470",
  "modified": "2026-10-16T10:31:12.099912269Z",
  "published": "2026-10-15T16:36:09.597Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77470.json"
    },
    {
      "type": "FIX",
      "url": "https://github.com/LycheeOrg/Lychee/commit/24e6e11f1da131ed20b192d7d7b7ca9084451a2f"
    },
    {
      "type": "FIX",
      "url": "https://github.com/LycheeOrg/Lychee/pull/4514"
    },
    {
      "type": "WEB",
      "url": "https://github.com/LycheeOrg/Lychee/releases/tag/v7.7.1"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/LycheeOrg/Lychee/security/advisories/GHSA-476v-jr53-8rxc"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-77470"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Lychee: Webshop checkout lets the client override the payment `amount` sent to the gateway via malicious crafted POST request"
}