CVE-2026-55219
MEDIUMPaymenter: Race condition in payWithCredit() enables credit double-spend
Blast Radius
paymenter/paymenterReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Paymenter is a free and open-source webshop solution for management of hosting services. In versions prior to 1.5.5, the credit payment implementation in app/Livewire/Invoices/Show.php executes a pessimistic row lock (lockForUpdate()) outside of an active database transaction. Because MySQL/MariaDB requires an enclosing transaction to enforce row-level locks, the guard is ineffective. Concurrent payment requests can exploit this race condition to read the same credit balance simultaneously, allowing users to pay multiple invoices using the same credit balance. In database systems like MySQL, a row lock only works inside a formal transaction; without one, the lock is completely ignored. Because there is no active lock, two payment requests sent at the exact same millisecond can look at the database at the same time. Both requests see the original credit balance, decide it is sufficient, and approve the payment. Because the payment processes successfully through ExtensionHelper::addPayment(), the application provisions the corresponding services or digital goods, resulting in direct financial or resource loss to the platform. This issue has been fixed in version 1.5.5.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | paymenter/paymenter | all versions | 1.5.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for paymenter/paymenter. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update paymenter/paymenter to 1.5.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-55219 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-55219 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-55219. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-55219 in your dependencies?
O3 detects CVE-2026-55219 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.