CVE-2026-77470

Impact

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.

Affected products

Versions were read from the advisory text. No structured product data has been published for this record yet.

Weakness classification

References

• NVD record
• CVE.org record
• 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