CVE-2026-43918 Auth bypass in FOSSBilling
Suspended or inactive users retain access via existing sessions and tokens because status checks are missing, allowing unauthorized access to billing data.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-43918?
CVE-2026-43918 is a high-severity authentication bypass vulnerability in FOSSBilling, published on 6 Jul 2026. Any signed-in user can exploit it over the network, 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, when a client or staff/admin account is suspended or marked inactive, existing authenticated sessions are not invalidated. The session identity loaders in src/di.php (loggedin_client and loggedin_admin) only reject sessions if the backing account record no longer exists in the database. They do not verify that the account's status is still active. This allows a suspended or deactivated user to retain full access until their session naturally expires. This issue has been fixed in version 0.8.0.
Weakness: CWE-613
Which versions are affected by CVE-2026-43918?
How do I fix CVE-2026-43918?
No fix has been published for CVE-2026-43918 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-43918 being exploited?
There is no known exploitation of CVE-2026-43918 in the wild and no public exploit code.
Sources
Also known as CVE-2026-43919, GHSA-qv6c-v49w-8g2j.