CVE-2026-44583
MEDIUMPaymenter: Blind Unauthenticated SSRF on the Paypal gateway module
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 1.5.0, 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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | paymenter/paymenter | all versions | 1.5.0 |
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 1.5.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44583 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-2026-44583 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-2026-44583. 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-2026-44583 in your dependencies?
O3 detects CVE-2026-44583 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.