CVE-2026-47741

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

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.

Multiple concurrent operations access a shared resource without proper synchronization, producing unpredictable results depending on timing. Typical impact: TOCTOU exploits, data corruption, or privilege escalation.

CVE-2026-47741 has a CVSS score of 5.9 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.8.0); upgrading removes the vulnerable code path.

Kodem intelligence

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

1. What is CVE-2026-47741? CVE-2026-47741 is a medium-severity race condition vulnerability in shopper/cart (composer), affecting versions < 2.8.0. It is fixed in 2.8.0. Multiple concurrent operations access a shared resource without proper synchronization, producing unpredictable results depending on timing.
2. How severe is CVE-2026-47741? CVE-2026-47741 has a CVSS score of 5.9 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of shopper/cart are affected by CVE-2026-47741? shopper/cart (composer) versions < 2.8.0 is affected.
4. Is there a fix for CVE-2026-47741? Yes. CVE-2026-47741 is fixed in 2.8.0. Upgrade to this version or later.
5. Is CVE-2026-47741 exploitable, and should I be worried? Whether CVE-2026-47741 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-47741 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-47741? Upgrade shopper/cart to 2.8.0 or later.