CVE-2026-43928 FOSSBilling: Payment amount not validated in PayPalEmail adapter allows invoice underpayment

FOSSBilling is a free, open-source billing and client management system. Prior to version 0.8.0, the PayPalEmail payment adapter accepts PayPal IPN callbacks and credits the IPN-supplied amount mcgross to the client's balance without validating it against the invoice total. Combined with a $0.05...