Vulnerability Description
FOSSBilling is a free, open-source billing and client management system. Starting in version 0.5.4 and prior to version 0.8.0, an authorization bypass in the API role handling allows unauthenticated access to privileged `/api/system/*` endpoints. Because `system` resolves to the cron admin identity, attackers can invoke admin API methods without valid credentials, session, or CSRF token. Version 0.8.0 patches the issue. Some workarounds are available. Block external access to `/api/system/*` at reverse proxy/WAF, restrict API access by trusted source IPs only (`api.allowed_ips`), rotate all admin/client API tokens immediately, invalidate active sessions and reset high-privilege credentials, and/or review API request logs for suspicious `/api/system/` access and treat as potential incident.
Related Weaknesses (CWE)
References
- https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-57mv-jm88-66
- https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-78x5-c8gw-82
- https://www.vulncheck.com/blog/fossbilling-auth-bypass-ssti-rce
FAQ
What is CVE-2026-27604?
CVE-2026-27604 is a documented vulnerability. FOSSBilling is a free, open-source billing and client management system. Starting in version 0.5.4 and prior to version 0.8.0, an authorization bypass in the API role handling allows unauthenticated a...
How severe is CVE-2026-27604?
CVSS scoring is not yet available for CVE-2026-27604. Check NVD for updates.
Is there a patch for CVE-2026-27604?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.