# GHSA-78vr-q6cf-c7p6: Craft Commerce: Partial Payment Amount Without Lower Bound Validation

> Attackers can submit zero or negative payment amounts to bypass payment validation, potentially obtaining free order fulfillment.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 19 Jun 2026

## What is GHSA-78vr-q6cf-c7p6?

GHSA-78vr-q6cf-c7p6 is a vulnerability in craftcms/commerce, published on 19 Jun 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

### Summary

The `Order::setPaymentAmount()` method accepts any float value without enforcing a minimum positive amount. The PaymentsController casts the user-supplied 'paymentAmount' parameter directly to float with no lower-bound check. 

### Details

When the store has 'Allow Partial Payment on Checkout' enabled, a user can submit a payment amount of $0.00 or even a negative value, potentially marking orders as paid without a valid transaction.

<img width="690" height="80" alt="image" src="https://github.com/user-attachments/assets/78b653a6-ccae-4ce4-b71b-fc38a7757d73" />

<img width="761" height="200" alt="image" src="https://github.com/user-attachments/assets/665a235f-62c2-45fe-aa41-c3f266881c77" />

### PoC

_Complete instructions, including specific configuration details, to reproduce the vulnerability._
<img width="606" height="144" alt="image" src="https://github.com/user-attachments/assets/a04a6de2-7c5f-4837-aed6-58756e246b80" />

### Impact
On stores with partial payment enabled, a customer may be able to set an arbitrarily small payment amount. Gateway behavior varies — some will process $0.00 transactions, effectively giving free order fulfillment.

**Remediation**

<img width="718" height="98" alt="image" src="https://github.com/user-attachments/assets/aa64b696-9749-45e4-97f6-8d7299cdf1d6" />

## Which versions are affected by GHSA-78vr-q6cf-c7p6?

4 open source packages ship an affected version, including craftcms/commerce.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `craftcms/commerce` | Packagist | From 4.0.0 | 4.11.2 |
| `craftcms/commerce` | Packagist | From 4.0.0 | 4.11.2 |
| `craftcms/commerce` | Packagist | From 5.0.0 | 5.6.5 |
| `craftcms/commerce` | Packagist | From 5.0.0 | 5.6.5 |

## How do I fix GHSA-78vr-q6cf-c7p6?

Upgrade craftcms/commerce to a fixed version for your release line: 4.11.2 or 5.6.5.

## Is GHSA-78vr-q6cf-c7p6 being exploited?

There is no known exploitation of GHSA-78vr-q6cf-c7p6 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-78vr-q6cf-c7p6 and fix it if it is affected.

What it is: GHSA-78vr-q6cf-c7p6 is a vulnerability in craftcms/commerce, published on 19 Jun 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of GHSA-78vr-q6cf-c7p6 in the wild and no public exploit code.

Affected packages and fixed versions:
- craftcms/commerce (Packagist): affected from 4.0.0; fixed in 4.11.2
- craftcms/commerce (Packagist): affected from 4.0.0; fixed in 4.11.2
- craftcms/commerce (Packagist): affected from 5.0.0; fixed in 5.6.5
- craftcms/commerce (Packagist): affected from 5.0.0; fixed in 5.6.5

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/GHSA-78vr-q6cf-c7p6/ (Markdown: https://insights.sbomify.com/GHSA-78vr-q6cf-c7p6/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-78vr-q6cf-c7p6

---
From sbomify Insights: https://insights.sbomify.com/GHSA-78vr-q6cf-c7p6/
Summaries are generated and may contain mistakes; the official description above is the record.