CVE-2026-77470Public exploitNetwork attack vectorHinoki check available

Underpayment via client-controlled checkout parameter overwrite

Published Oct 15, 2026 · Updated Oct 15, 2026

Payment tampering in Lychee before 7.7.1 allows remote attackers to underpay for webshop orders via checkout requests. CheckoutService::preparePurchaseParameters() merges unrestricted additional_data after trusted purchase parameters, allowing client keys to replace the computed amount. Exploitation requires an enabled Supporter or Pro webshop, a purchasable item, and a non-PayPal Omnipay gateway; no account is required, and auto-fulfillment releases goods despite underpayment.

CVSS severity8.3
High
EPSS probability0.45%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Payment tampering in Lychee before 7.7.1 allows remote attackers to underpay for webshop orders via checkout requests. CheckoutService::preparePurchaseParameters() merges unrestricted additional_data after trusted purchase parameters, allowing client keys to replace the computed amount. Exploitation requires an enabled Supporter or Pro webshop, a purchasable item, and a non-PayPal Omnipay gateway; no account is required, and auto-fulfillment releases goods despite underpayment.

The record

CVE
CVE-2026-77470
Published
Oct 15, 2026
Updated
Oct 15, 2026
Vendor
LycheeOrg
Product
Lychee
Classifications
CWE-472, CWE-20, CWE-915
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 7.7.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

LycheeOrg · Lycheeversion=< 7.7.1

Published CVSS scores

8.3GitHub_MCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N
7.5LycheeOrgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-472External Control of Assumed-Immutable Web Parameter
CWE-20Improper Input Validation
CWE-915Improperly Controlled Modification of Dynamically-Determined Object Attributes

Public exploit references

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Technologies

Your stack

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Your stack

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