Vulnerability · Published Jun 24, 2026 · Assigned by GitHub_M

CVE-2026-27708FOSSBilling: IDOR in Servicecustom Client API allows cross-client data access

High 7.1

In plain English

A high-severity improper access control in FOSSBilling from FOSSBilling. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities).

Severity (CVSS 4.0)7.1High
Exploit odds (30 days)0.4%top 69.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

FOSSBilling is a free, open-source billing and client management system. In versions 0.7.2 and prior, the Servicecustom Client API's __call method accepts an order_id parameter and fetches the associated order without verifying the authenticated client owns it, potentially exposing cross-client data through IDOR. An authenticated client can access any other client's custom service by guessing sequential order IDs. This can lead to a confidentiality breach — attackers can read client PII (name, email, phone, address, company details, VAT number) and service configuration data belonging to other clients. This issue has been fixed in version 0.8.0.

Affected products (as reported)

VendorProductVersions
FOSSBilling FOSSBilling < 0.8.0

Weakness: CWE-284, CWE-639, CWE-862 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

References