CVE-2026-27604

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.

Affected Software

VendorProductVersion RangeStatus
FOSSBillingFOSSBilling>= 0.5.4, < 0.8.0affected

Weaknesses

  • CWE-200: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
  • CWE-306: CWE-306: Missing Authentication for Critical Function
  • CWE-862: CWE-862: Missing Authorization
  • CWE-863: CWE-863: Incorrect Authorization

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: total

References