{"id":"CVE-2026-56831","state":"PUBLISHED","title":"Shopper: Negative discount values accepted and propagated through order calculation pipeline","description":"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.","publishedAt":"2026-09-15T17:42:09.495Z","updatedAt":"2026-09-16T14:41:52.114Z","severity":{"score":6.5,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["shopperlabs shopper"],"affected":[{"vendor":"shopperlabs","product":"shopper","versions":[{"version":"< 2.9.0","status":"affected"}]}],"references":["https://github.com/shopperlabs/shopper/security/advisories/GHSA-5vf4-452p-jjhf","https://github.com/shopperlabs/shopper/pull/528","https://github.com/shopperlabs/shopper/commit/967e616281ded1a0050d9102858ecd7dd7f66a41","https://github.com/shopperlabs/shopper/releases/tag/v2.9.0"],"weaknesses":["CWE-20"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/56xxx/CVE-2026-56831.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-56831","state":"PUBLISHED","datePublished":"2026-09-15T17:42:09.495Z","dateUpdated":"2026-09-16T14:41:52.114Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-23T14:55:09.117Z"},"containers":{"cna":{"title":"Shopper: Negative discount values accepted and propagated through order calculation pipeline","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"shopperlabs","product":"shopper","versions":[{"version":"< 2.9.0","status":"affected"}]}],"references":[{"url":"https://github.com/shopperlabs/shopper/security/advisories/GHSA-5vf4-452p-jjhf","name":"https://github.com/shopperlabs/shopper/security/advisories/GHSA-5vf4-452p-jjhf","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/shopperlabs/shopper/pull/528","name":"https://github.com/shopperlabs/shopper/pull/528","tags":["x_refsource_MISC"]},{"url":"https://github.com/shopperlabs/shopper/commit/967e616281ded1a0050d9102858ecd7dd7f66a41","name":"https://github.com/shopperlabs/shopper/commit/967e616281ded1a0050d9102858ecd7dd7f66a41","tags":["x_refsource_MISC"]},{"url":"https://github.com/shopperlabs/shopper/releases/tag/v2.9.0","name":"https://github.com/shopperlabs/shopper/releases/tag/v2.9.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-20","lang":"en","description":"CWE-20: Improper Input Validation","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-15T17:42:09.495Z"},"source":{"advisory":"GHSA-5vf4-452p-jjhf","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/shopperlabs/shopper/security/advisories/GHSA-5vf4-452p-jjhf","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-16T14:41:46.439666Z","id":"CVE-2026-56831","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-16T14:41:52.114Z"}}]}}}