CVE-2026-43925 FOSSBilling: Mass assignment of group_id in guest client registration allows unauthorized promo code use
Unauthenticated attackers can assign themselves to privileged client groups during registration to bypass restrictions and use unauthorized promo codes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-43925?
CVE-2026-43925 is a medium-severity missing authorization vulnerability in FOSSBilling, published on 6 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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).
Weakness: CWE-915
Which versions are affected by CVE-2026-43925?
How do I fix CVE-2026-43925?
No fix has been published for CVE-2026-43925 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-43925 being exploited?
There is no known exploitation of CVE-2026-43925 in the wild and no public exploit code.
Sources
Also known as GHSA-q4rq-9844-r9w2.