CVE-2026-27604 (GCVE-0-2026-27604)

Vulnerability from cvelistv5 – Published: 2026-06-23 14:25 – Updated: 2026-06-23 15:11
VLAI
Title
FOSSBilling: Improper API Role Validation (system) Enables Unauthenticated Access to Privileged Admin Functions
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.
Severity
10 (Critical)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
SSVC
Exploitation: none Automatable: yes Technical Impact: total
CISA Coordinator (v2.0.3)
CWE
  • CWE-200 - Exposure of Sensitive Information to an Unauthorized Actor
  • CWE-306 - Missing Authentication for Critical Function
  • CWE-862 - Missing Authorization
  • CWE-863 - Incorrect Authorization
Assigner
References
Impacted products
Vendor Product Version
FOSSBilling FOSSBilling Affected: >= 0.5.4, < 0.8.0
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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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