Skip to main content
← All vulnerabilities
CVE-2026-27604

FOSSBilling: Improper API Role Validation (system) Enables Unauthenticated Access to Privileged Admin Functions

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 0.8.0
1 Nuclei template
  • Exploitation: none
  • Automatable: yes
  • Technical impact: total

Summary

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.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: yes · Technical impact: total

  3. Record last updated

Affected versions

  • FOSSBilling FOSSBilling

    From 0.5.4 · fixed in 0.8.0

References 4

GitHub · FOSSBilling/FOSSBilling

vulncheck.com

GitHub · projectdiscovery/nuclei-templates