CVE-2026-44583
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk34th percentile - higher than 34% of all known CVEs
Summary
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.
Risk Assessment
The risk includes blind SSRF, which could enable internal network scanning, access to sensitive services, or data exfiltration via side channels.
Recommendation
Immediately upgrade to version 1.5.0 or later and implement validation of the PAYPAL-CERT-URL header, including an allowlist of hosts and signature verification.
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.
Original NVD description (English source)
Paymenter is a free and open-source webshop solution for management of 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, allowing attackers to control the destination of the request. No allowlist, validation, or signature verification is applied to the header before usage. As a result, the application can be coerced into performing HTTP requests to attacker-controlled or internal network destinations. This vulnerability allows remote unauthenticated attackers to induce server-side HTTP GET requests to arbitrary external or internal endpoints. Depending on network configuration, this may lead to: blind SSRF to external attacker-controlled systems, and potential access to internal network services No direct response data is returned to the attacker (blind SSRF), but the issue may still enable sensitive network probing or data exfiltration via side channels. This issue has been fixed in version 1.5.0.