CVE-2026-42331
Description
FOSSBilling is a free, open-source billing and client management system. Prior to version 0.8.0, the Guest API invoice/update endpoint is missing an authorization check present in other invoice-related endpoints, allowing an unauthenticated user with knowledge of an invoice hash to modify the payment gateway associated with an unpaid invoice. An attacker who obtains an invoice hash, which may leak through shared URLs, referrer headers, or email links, can change the `gateway_id` on an unpaid invoice to any payment gateway configured in the system. This does not allow redirecting payments to an arbitrary external endpoint, as the gateway must already be installed and configured by an administrator. The practical impact is further limited by the `invoice_accessible_from_hash` system setting. Version 0.8.0 contains a patch. No known workarounds are available.
Weakness Type (CWE)
References
Frequently Asked Questions
What is CVE-2026-42331? +
How do I check if I'm vulnerable to CVE-2026-42331? +
Related Vulnerabilities
An improper access control vulnerability in the canonical-livepatch snap client prior to version 10.15.0 allows a local unprivileged user to …
A missing authentication vulnerability exists in the Altium 365 SearchService. A legacy SOAP endpoint exposes search index operations without requiring …
Inadequate access control in the registration process in Fullstep V5, which could allow unauthenticated users to obtain a valid JWT …
A weakness in SpiceJet’s public booking retrieval page permits full passenger booking details to be accessed using only a PNR …
A Missing Authentication for Critical Function vulnerability in the GRUB configuration used B&R APROL <4.4-01 may allow an unauthenticated physical …
Penetration Testing engineers at Amazon have identified a security flaw related to request handling in the web server component that …