CVE-2026-112374 Details
Description
FOSSBilling before 0.8.9 contains a Cross-Site Request Forgery vulnerability in the staff guest login endpoint (POST /api/guest/staff/login) that allows remote attackers to force authentication because checkGuestClientAuthentication() only allowlists client_login and client_create, leaving staff_login without CSRF or Origin validation. Attackers can host an auto-submitting HTML form with attacker-controlled credentials to silently log a victim's browser into the attacker's staff account.
A Cross-Site Request Forgery (CSRF) vulnerability has been identified in FOSSBilling versions prior to 0.8.9. The issue resides in the staff guest login endpoint (POST /api/guest/staff/login), where the checkGuestClientAuthentication() function fails to properly validate CSRF tokens or the Origin header for staff_login. This oversight allows remote attackers to exploit the vulnerability by sending an auto-submitting HTML form with controlled credentials, thereby logging the victim into the attacker's staff account.
Users are advised to update to FOSSBilling version 0.8.9 or later, where this vulnerability has been addressed.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Oct 30, 2026CISA-ADP
Assessed Nov 5, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/FOSSBilling/FOSSBilling/releases/tag/0.8.9 | [email protected] | Release NotesVendor |
| https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-h7w3-wp25-gf86 | [email protected] | AdvisoryBroken LinkVendor |
| https://www.vulncheck.com/advisories/fossbilling-before-login-csrf-via-staff-guest-login-api | [email protected] | AdvisoryRemedy |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-352 | Cross-Site Request Forgery (CSRF) | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| FOSSBilling | >= 0.1.0, < 0.8.9 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Nov 5, 2026 | CVE Modified | CISA-ADP |
| Oct 30, 2026 | New CVE Received | [email protected] |