GHSA-9RH9-HF3W-9FGG

Vulnerability from github – Published: 2026-05-18 16:37 – Updated: 2026-06-08 20:07
VLAI
Summary
shopper/framework: Race condition on Discount.usage_limit allows silent over-redemption
Details

Impact

CreateOrderFromCartAction::execute previously created the Order row before checking and incrementing the discount's total_use counter. Under concurrent checkout pressure (Black Friday, flash sale, viral coupon), the global usage_limit was silently exceeded: orders were committed with the discount fully applied to price_amount while the counter blocked at usage_limit. The merchant had no signal that an over-redemption had occurred.

A second related bug: usage_limit_per_user was effectively a no-op because the counter it relied on (DiscountDetail.total_use) was never incremented anywhere in the codebase. The per-user check therefore always saw 0 uses and validation passed regardless of how many times the same customer had previously redeemed the coupon. For eligibility = Everyone the per-user limit could not fire at all because the underlying DiscountDetail row only exists for eligibility = Customers.

Direct financial loss: each over-redemption is a discount the merchant did not intend to grant.

Patches

Fixed in v2.8.0. CreateOrderFromCartAction now:

  • Reserves the discount slot atomically before the order row is created, inside the same DB::transaction with lockForUpdate and a compare-and-swap on total_use.
  • Throws DiscountLimitReachedException::global and rolls back the transaction when the global limit was exhausted between cart validation and commit. No order is committed.
  • Throws DiscountLimitReachedException::perUser and rolls back when the discount is restricted to one use per customer and the customer has already redeemed it.
  • Snapshots discount_id, discount_code, discount_type, discount_value_at_apply and discount_currency_code onto the orders table for resilience against later discount edits or deletions.

DiscountValidator was updated to perform the same Order-based per-user check at cart-apply time so the rejection is surfaced before checkout.

Upgrade via:

composer require shopper/cart:^2.8 shopper/core:^2.8 php artisan migrate

Workarounds

None. Upgrade to v2.8.0.

Resources

  • Issue: https://github.com/shopperlabs/shopper/issues/510
  • Pull request: https://github.com/shopperlabs/shopper/pull/511
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization
Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "shopper/cart"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.8.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-47741"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-362"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-18T16:37:20Z",
    "nvd_published_at": "2026-05-29T19:16:25Z",
    "severity": "MODERATE"
  },
  "details": "## Impact\n\n`CreateOrderFromCartAction::execute` previously created the `Order` row before checking and incrementing the discount\u0027s `total_use` counter. Under concurrent checkout pressure (Black Friday, flash sale, viral coupon), the global `usage_limit` was silently exceeded: orders were committed with the discount fully applied to `price_amount` while the counter blocked at `usage_limit`. The merchant had no signal that an over-redemption had occurred.\n\nA second related bug: `usage_limit_per_user` was effectively a no-op because the counter it relied on (`DiscountDetail.total_use`) was never incremented anywhere in the codebase. The per-user check therefore always saw `0` uses and validation passed regardless of how many times the same customer had previously redeemed the coupon. For `eligibility = Everyone` the per-user limit could not fire at all because the underlying `DiscountDetail` row only exists for `eligibility = Customers`.\n\nDirect financial loss: each over-redemption is a discount the merchant did not intend to grant.\n\n## Patches\n\nFixed in `v2.8.0`. `CreateOrderFromCartAction` now:\n\n- Reserves the discount slot atomically before the order row is created, inside the same `DB::transaction` with `lockForUpdate` and a compare-and-swap on `total_use`.\n- Throws `DiscountLimitReachedException::global` and rolls back the transaction when the global limit was exhausted between cart validation and commit. No order is committed.\n- Throws `DiscountLimitReachedException::perUser` and rolls back when the discount is restricted to one use per customer and the customer has already redeemed it.\n- Snapshots `discount_id`, `discount_code`, `discount_type`, `discount_value_at_apply` and `discount_currency_code` onto the `orders` table for resilience against later discount edits or deletions.\n\n`DiscountValidator` was updated to perform the same Order-based per-user check at cart-apply time so the rejection is surfaced before checkout.\n\nUpgrade via:\n\n`composer require shopper/cart:^2.8 shopper/core:^2.8`\n`php artisan migrate`\n\n## Workarounds\n\nNone. Upgrade to `v2.8.0`.\n\n## Resources\n\n- Issue: https://github.com/shopperlabs/shopper/issues/510\n- Pull request: https://github.com/shopperlabs/shopper/pull/511\n- CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization",
  "id": "GHSA-9rh9-hf3w-9fgg",
  "modified": "2026-06-08T20:07:26Z",
  "published": "2026-05-18T16:37:20Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/shopperlabs/shopper/security/advisories/GHSA-9rh9-hf3w-9fgg"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-47741"
    },
    {
      "type": "WEB",
      "url": "https://github.com/shopperlabs/shopper/issues/510"
    },
    {
      "type": "WEB",
      "url": "https://github.com/shopperlabs/shopper/pull/511"
    },
    {
      "type": "WEB",
      "url": "https://github.com/shopperlabs/shopper/commit/fcd0c5920588702df5b874f432b1042abd77a50b"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/shopperlabs/shopper"
    },
    {
      "type": "WEB",
      "url": "https://github.com/shopperlabs/shopper/releases/tag/v2.8.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "shopper/framework: Race condition on Discount.usage_limit allows silent over-redemption"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Loading…

Loading…

Loading…

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.


Loading…