CVE-2026-112374: medium-severity vulnerability in FOSSBilling
FOSSBilling before 0.8.9 Login CSRF via Staff Guest Login API
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.1epss 0.2%
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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Affected products
FOSSBilling · FOSSBillingRelated CVEs — FOSSBilling
In the same product, most dangerous first.
CVE-2026-28496CRITICALFOSSBilling: Server-side template injection in Twig template rendering enables information disclosure and RCEEPSS 1.9%CVE-2026-27604CRITICALFOSSBilling: Improper API Role Validation (system) Enables Unauthenticated Access to Privileged Admin FunctionsEPSS 1.3%CVE-2026-43920MEDIUMFOSSBilling: Unauthenticated update patcher endpoint allows remote maintenance executionEPSS 0.9%CVE-2026-53647MEDIUMFOSSBilling vulnerable to unauthenticated API key configuration disclosure via guest Serviceapikey get_info endpointEPSS 0.5%CVE-2026-43925MEDIUMFOSSBilling: Mass assignment of group_id in guest client registration allows unauthorized promo code useEPSS 0.5%CVE-2026-33543CRITICALFOSSBilling: Authentication bypass allows unauthenticated administrator creationEPSS 0.4%