Bitcoin Cash SV (BSV), a new fork of Bitcoin Cash (BTC), faced new controversy on Dec. 8 after a researcher reportedly showed how any user could spend the same coins twice on its network in a “0-conf transaction.”
Bitcoin Cash, which was created in a hard fork from Bitcoin (BTC) in August 2017, uses 0-conf (or zero-conf) to allow almost instant transactions, meaning they are almost always confirmed in the following block.