Answer in brief
CVE-2026-56831 records a Medium severity (CVSS 6.5) vulnerability in Shopper: Negative discount values accepted and propagated through order calculation pipeline. The current sources do not mark it as known exploited. The current feed maps shopper/framework (composer), shopperlabs/shopper (generic), shopper/framework (packagist). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 6.5. 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.
The current feed maps shopper/framework (composer), shopperlabs/shopper (generic), shopper/framework (packagist). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| shopper/frameworkcomposer | <2.9.0 | 2.9.0 |
| shopperlabs/shoppergeneric | <2.9.0 | 2.9.0 |
| shopper/frameworkpackagist | >=0 <2.9.0 | 2.9.0 |
Published upstream
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 30, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 11, 2026
Shopper is a Headless e-commerce Admin Panel. Prior to 2.9.0, the /cpanel/discounts administrative interface accepts negative fixed_amount discount values, persists them in sh_discounts, and passes them through vendor/shopper/cart/src/Discounts/DiscountCalculator.php and vendor/shopper/cart/src/Pipelines/Calculate.php without enforcing a positive-value invariant. Because the calculation subtracts discountTotal from the subtotal, a negative discount increases the resulting order total instead of reducing it. Malformed discount records can therefore cause incorrect pricing and financial data integrity failures, although the advisory does not establish a customer-facing exploitation path. This issue is fixed in version 2.9.0.
Quoted source text, attributed separately from HOL analysis.