ZCashTransaction::TotalInputsAmount overflow with large input values

State: open · created 2026-02-27 · updated 2026-02-27 · discovered via tracked:previous · matched title:zcashtransaction, body:zcashtransaction

ZCashTransaction::TotalInputsAmount sums input amounts using plain addition without overflow checking. If inputs sum to more than INT64_MAX, the result silently wraps around, potentially causing incorrect fee calculations or allowing transactions with negative effective fees. Severity: High — integer overflow in financial calculation code. PR: https://github.com/brave/brave-core/pull/34260

State: open · created 2026-02-27 · updated 2026-10-14 · discovered via search:orchard is:pr, search:zcash is:pr · matched title:zcashtransaction, body:zcashtransaction

Summary Change ZCashTransaction::TotalInputsAmount() return type from uint64_t to base::CheckedNumeric to detect integer overflow when summing UTXO input amounts. Bug Description TotalInputsAmount() used raw uint64_t arithmetic to sum transparent and orchard input amounts. If a transaction had many inputs with large amounts, the sum could silently wrap around, producing a much smaller value than the actual total. This is inconsistent with ValidateAmounts() in the same file,…