{"id":"CVE-2026-56831","summary":"Shopper: Negative discount values accepted and propagated through order calculation pipeline","details":"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.","aliases":["GHSA-5vf4-452p-jjhf"],"modified":"2026-09-18T03:30:47.683907208Z","published":"2026-09-15T17:42:09.495Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-20"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56831.json"},"references":[{"type":"WEB","url":"https://github.com/shopperlabs/shopper/releases/tag/v2.9.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56831.json"},{"type":"ADVISORY","url":"https://github.com/shopperlabs/shopper/security/advisories/GHSA-5vf4-452p-jjhf"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56831"},{"type":"FIX","url":"https://github.com/shopperlabs/shopper/commit/967e616281ded1a0050d9102858ecd7dd7f66a41"},{"type":"FIX","url":"https://github.com/shopperlabs/shopper/pull/528"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/shopperlabs/shopper","events":[{"introduced":"0"},{"fixed":"967e616281ded1a0050d9102858ecd7dd7f66a41"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"2.9.0"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v2.8.1","v2.8.0","v2.7.3","v2.7.2","v2.7.1","v2.7.0","v2.6.4","v2.6.3","v2.6.2","v2.6.1","v2.6.0","v2.5.0","v2.4.3","v2.4.2","v2.4.1","v2.4.0","v2.3.3","v2.3.2","v2.3.1","v2.3","v2.2.7","v2.2.6","v2.2.5","v2.2.4","v2.2.3","v2.2.2","v2.2.1","v2.2","v2.1.6","v2.1.5","v2.1.4","v2.1.3","v2.1.2","v2.1.1","v2.1","v2.0.3","v2.0.2","v2.0.1","v2.0.0","v2.0.0-beta21","v2.0.0-beta20","v2.0.0-beta19","v2.0.0-beta18","v2.0.0-beta17","v2.0.0-beta16","v2.0.0-beta15","v2.0.0-beta14","v2.0.0-beta13","v2.0.0-beta12","v2.0.0-beta11","v2.0.0-beta10","v2.0.0-beta9","v2.0.0-beta8","v2.0.0-beta7","v2.0.0-beta6","v2.0.0-beta5","v2.0.0-beta4","v2.0.0-beta3","v2.0.0-beta2","v2.0.0-beta","v1.1.2","v1.1.1","v1.1","v1.0.9","v1.0.8","v1.0.7","v1.0.6","v1.0.5","v1.0.4","V1.0.4","v1.0.3","v1.0.2","v1.0.1","v1.0","v0.0.26","v0.0.25","v0.0.24","v0.0.23","v0.0.22","v0.0.21","v0.0.20","v0.0.19","v0.0.18","v0.0.17","v0.0.16","v0.0.15","v0.0.14","v0.0.13","v0.0.12","v0.0.11","v0.0.10","v0.0.9","v0.0.8","v0.0.7","v0.0.6","v0.0.5","v0.0.4","v0.0.3","v0.0.2","v0.0.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-56831.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N"}]}