Bitcoin Library bitcoinjs-lib Patches Two Flaws Causing Severe Transaction Fee Understatements

Developers of bitcoinjs-lib have patched two high-severity vulnerabilities that caused applications processing partially signed Bitcoin transactions to drastically underestimate miner fees. The accounting discrepancies bypassed standard fee-rate warnings, allowing excessive fee payments. In one demonstration on version 7.0.1, an actual fee of 900,000,000 satoshis was calculated as just 200 satoshis, while another bug caused a 91,000-satoshi fee to be miscalculated as 1,000 satoshis. Fixes have been deployed across versions 5.2.2, 6.1.9, and 7.0.4. No confirmed losses or active exploitation have been reported.