CVE intelligence and bounded remediation

CVE-2026-23513 — FOSSBilling is a free, open-source billing and client management system

High CVSS 7.1

FOSSBilling is a free, open-source billing and client management system. In versions 0.7.2 and prior, a query-construction flaw in client list endpoints allowed authenticated clients to bypass tenant scoping and retrieve other clients’ data. Details In ServiceTransaction::getSearchQuery() and Order\Service::getSearchQuery(), OR-based search/action filters were appended without grouping, allowing SQL operator precedence to evaluate OR clauses independently of the enforced client_id constraint. Crafted requests could therefore return records and metadata belonging to other clients, including identifiers, amounts, status, timestamps, and related fields. This issue was fixed in version 0.8.0.

Severity
High
CVSS
7.1 (4.0)
Published
2026-06-23
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-863

Affected products

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Matched remediation archetype

Authorization bypass, IDOR, and cross-tenant access

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Check exposure

  • Map object and action authorization checks across API, UI, batch, import/export, and background-job paths.
  • Identify tenant, ownership, role, and policy boundaries for affected resources and administrative operations.
  • Use synthetic fixtures to compare intended access matrices without accessing another user's real data.

Remediate safely

  • Enforce server-side authorization at each resource access and state transition using the authenticated principal and trusted tenant context.
  • Scope data queries by tenant and ownership; treat client-supplied identifiers, roles, and policy claims as untrusted.
  • Add deny-by-default policy tests for horizontal and vertical access across every affected transport.

Authoritative sources

Complete CVE record and remediation plan

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