{"cve":"CVE-2026-77470","nvd":{"published":"2026-10-15T17:17:27.997","modified":"2026-10-15T21:08:49.703","status":"Deferred","description":"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_v4":{"vector":"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","score":8.3},"cvss_v3":null,"cwes":["CWE-20","CWE-472","CWE-915"],"references":["https://github.com/LycheeOrg/Lychee/commit/24e6e11f1da131ed20b192d7d7b7ca9084451a2f","https://github.com/LycheeOrg/Lychee/pull/4514","https://github.com/LycheeOrg/Lychee/releases/tag/v7.7.1","https://github.com/LycheeOrg/Lychee/security/advisories/GHSA-476v-jr53-8rxc","https://github.com/LycheeOrg/Lychee/security/advisories/GHSA-476v-jr53-8rxc"],"products":[],"source":"nvd","synced_at":"2026-10-19T23:00:53.604569364+00:00"},"epss":{"cve":"CVE-2026-77470","score":0.00451,"percentile":0.38945,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}