CVE-2026-71537
MediumCVSS 6.5Exploitation Probability (EPSS)
Low risk23th percentile - higher than 23% of all known CVEs
Summary
In Paymenter prior to 1.5.7, doUpgrade() relied on Service::upgradable to check for a pending upgrade and then incremented credit without a DB transaction or lock. An authenticated customer with an active downgradable service could submit concurrent downgrade requests, creating multiple upgrade records and incrementing the same credit balance multiple times.
Risk Assessment
A customer can obtain multiple refunds for a single downgrade, causing financial loss for the hosting shop operator.
Recommendation
Upgrade Paymenter to version 1.5.7 or later, which secures the upgrade and credit increment operations.
Other vulnerabilities in Paymenter
See all- CVE-2026-55219Medium
Paymenter versions prior to 1.5.5 have a race condition in the credit payment implementation. The row lock (lockForUpdate()) is executed outside an active database transaction, making it ineffective in MySQL/MariaDB. Concurrent payment requests can read the same credit balance and reuse the same funds.
- CVE-2026-47198High
Paymenter before 1.5.1 has a vulnerability in the checkout component allowing authenticated users to inject arbitrary key-value pairs into server provisioning parameters, potentially overriding resource limits without privileges.
- CVE-2026-44585Medium
In Paymenter prior to version 1.5.0, the ticket creation endpoint accepts a user-supplied service identifier without enforcing ownership validation, allowing authenticated users to create support tickets referencing services belonging to other accounts by modifying the service ID in the request.
- CVE-2026-44584Medium
Paymenter before version 1.5.0 fails to invalidate the email verification state after an email change. A verified account retains its verified status even after switching to an unverified address. This could lead to abuse of features gated behind verified status.
- CVE-2026-44583Medium
Paymenter is a free open-source webshop solution for hosting services. In versions prior to 1.5.0, the PayPal webhook endpoint /extensions/paypal/webhook processes the PAYPAL-CERT-URL HTTP header without validation, allowing attackers to control server-side HTTP request destinations. This value is passed directly into a server-side HTTP request via file_get_contents without allowlist, validation, or signature verification. The vulnerability allows remote unauthenticated attackers to trigger HTTP GET requests to arbitrary external or internal endpoints, potentially leading to blind SSRF and access to internal network services.
Original NVD description (English source)
Paymenter is a free and open-source webshop solution for management of hosting services. Prior to 1.5.7, app/Livewire/Services/Upgrade.php::doUpgrade() relies on Service::upgradable to check for a pending service upgrade and later executes $credit->increment('amount', abs($price)) without DB::transaction or lockForUpdate() spanning those operations. An authenticated customer with an active downgradable service can submit concurrent downgrade requests that each observe no pending upgrade, create separate upgrade records, and increment the same account credit balance, producing multiple spendable refunds for one downgrade. This issue is fixed in version 1.5.7.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS