What’s Vulnerable › Vulnerabilities

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

• Severity: high (CVSS 7.1 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-24 · updated 2026-06-25
• Weakness: CWE-284

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

• FOSSBilling: before 0.8.0

References

• https://github.com/FOSSBilling/FOSSBilling/releases/tag/0.8.0
• https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-p36w-9x66-488j

Get alerted when CVE-2026-27708 or the next vulnerability affects your stack