CVE-2026-55219 Paymenter: Race condition in payWithCredit() enables credit double-spend

What is CVE-2026-55219?

CVE-2026-55219 is a medium-severity vulnerability in Paymenter, published on 20 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official 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.

Weakness: CWE-362

Which versions are affected by CVE-2026-55219?

2 open source packages ship an affected version, including paymenter/paymenter.

How do I fix CVE-2026-55219?

Upgrade paymenter/paymenter to 1.5.5 or later.

Is CVE-2026-55219 being exploited?

There is no known exploitation of CVE-2026-55219 in the wild and no public exploit code.

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-pgcq-8grm-5rx9.