High · CVSS 8.3CVE-2026-77470

Lychee: Webshop checkout lets the client override the payment `amount` sent to the gateway via malicious crafted POST requestCVE-2026-77470

Answer in brief

CVE-2026-77470 records a High severity (CVSS 8.3) vulnerability in Lychee: Webshop checkout lets the client override the payment `amount` sent to the gateway via malicious crafted POST request. The current sources do not mark it as known exploited. The current feed maps LycheeOrg/Lychee (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 15, 2026Updated Oct 15, 2026Source checked Oct 15, 2026First seen by HOL Oct 15, 2026Material review Oct 15, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.3
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 8.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps LycheeOrg/Lychee (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
LycheeOrg/Lycheegeneric	<7.7.1	7.7.1

Recommended response

Check inventory. Check lockfiles and deployed manifests for LycheeOrg/Lychee.
Review the reported fix. Update LycheeOrg/Lychee to 7.7.1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 15, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.