Auth bypass in Fossbilling
CVE-2026-53643
FOSSBilling is a free, open-source billing and client management system. Versions prior to 0.8.0 allow low-privileged staff accounts to perform unauthorized actions via admin API endpoints. The root cause is a combination of the `can_always_access` module flag (which grants all staff access to certain modules) and insufficient permission checks or unsafe parameter handling on individual endpoints. Version 0.8.0 contains a fix. Some workarounds are available. Restrict staff accounts to only those who need access to sensitive settings and/or use a reverse proxy or WAF to restrict access to the affected endpoints to trusted IP addresses or higher-privilege roles.
Vulnerability class: Information Disclosure
Published · last modified .
EPSS exploit prediction
EPSS: 0.004 (26.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 26.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Fossbilling — versions < 0.8.0