{"id":"CVE-2026-112374","title":"FOSSBilling before 0.8.9 Login CSRF via Staff Guest Login API","summary":"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() on…","severity":"medium","cvss":4.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N","cvssSource":"cna","cwe":["CWE-352"],"vendor":"FOSSBilling","product":"FOSSBilling","affected":["FOSSBilling >= 0.1.0 < 0.8.9"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-05T21:23:53.494731Z"},"published":"2026-10-30","updated":"2026-11-05","sourceUpdated":"2026-11-05T21:24:07.055Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-112374","references":[{"url":"https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-h7w3-wp25-gf86","label":"Vendor Advisory"},{"url":"https://github.com/FOSSBilling/FOSSBilling/releases/tag/0.8.9","label":"Vendor Patch"},{"url":"https://www.vulncheck.com/advisories/fossbilling-before-login-csrf-via-staff-guest-login-api","label":"VulnCheck Advisory: FOSSBilling before 0.8.9 Login CSRF via Staff Guest Login API"}],"tags":["cve.org"],"epss":0.00172,"epssPercentile":0.06662,"ingestedAt":"2026-11-03T11:43:15.777Z","slug":"CVE-2026-112374","body":"## Overview\n\nFOSSBilling 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.\n\n## Affected\n\n- `FOSSBilling >= 0.1.0 < 0.8.9`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":24,"depthScoreParts":{"impact":23.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}