Vulnerability · Published Jul 6, 2026 · Assigned by GitHub_M
CVE-2026-43925FOSSBilling: Mass assignment of group_id in guest client registration allows unauthorized promo code use
Medium 6.9
In plain English
A medium-severity security flaw in FOSSBilling from FOSSBilling. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities).
Official description
FOSSBilling is a free, open-source billing and client management system. Prior to version 0.8.0, an unauthenticated mass assignment vulnerability in the client self-registration endpoint allows any visitor to assign themselves to an arbitrary client group during sign-up. Because client groups can gate promo code eligibility, an attacker may apply group-restricted discount codes and receive unauthorized discounts. Version 0.8.0 contains a patch. As a workaround, administrators can either remove group restrictions from promo codes or disable client self-registration (Settings → Clients → Disable signup).
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| FOSSBilling | FOSSBilling | < 0.8.0 |
Weakness: CWE-915 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N