FOSSBilling up to 0.7.x Servicecustom Client API order_id access control

Summaryinfo

A vulnerability classified as critical has been found in FOSSBilling up to 0.7.x. Affected by this issue is some unknown functionality of the component Servicecustom Client API. This manipulation of the argument order_id causes access control. This vulnerability is handled as CVE-2026-27708. The attack can be initiated remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in FOSSBilling up to 0.7.x. It has been declared as critical. Affected by this vulnerability is some unknown processing of the component Servicecustom Client API. The manipulation of the argument order_id with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-27708 since 02/23/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1068 for this issue.

Upgrading to version 0.8.0 eliminates this vulnerability. The upgrade is hosted for download at github.com.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Billing Software

Name

• FOSSBilling

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7

Website

• Product: https://github.com/FOSSBilling/FOSSBilling/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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