Posts tagged consensus_abuse.

A Bitcoin Core block containing a transaction that spends the same previous output twice reaches a validation path with no duplicate-input check: on 0.14.x this trips an internal assertion and crashes the node, and on 0.15.0-0.16.2 — when the duplicated output was created in an earlier block — it passes silently, letting the block's miner claim that output's value twice. Fixed in 0.16.3 / 0.17.0.