CVE-2026-44583 Paymenter: Blind Unauthenticated SSRF on the Paypal gateway module
Unauthenticated attackers can trigger server-side HTTP requests to arbitrary internal or external endpoints via the PayPal webhook header, enabling network probing and potential data exfiltration.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-44583?
CVE-2026-44583 is a medium-severity server-side request forgery vulnerability in Paymenter, published on 20 Jul 2026. An attacker can exploit it over the internet without logging in, 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 1.5.0, 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.
Weakness: CWE-918
Which versions are affected by CVE-2026-44583?
2 open source packages ship an affected version, including paymenter/paymenter.
| Package | Affected | Fixed in |
|---|---|---|
paymenter/paymenter Packagist | All versions | 1.5.0 |
paymenter/paymenter Packagist | All versions | 1.5.0 |
How do I fix CVE-2026-44583?
Upgrade paymenter/paymenter to 1.5.0 or later.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-44583 being exploited?
There is no known exploitation of CVE-2026-44583 in the wild and no public exploit code.
Sources
Also known as GHSA-7wwh-xcc3-9fcg.