An attacker exploited a bug in Blockstream's Elements open-source software to mint approximately 4,000 unbacked LBTC tokens

From the articleLiquid’s bitcoin (BTC) IOUs are fully backed again after a $320 million exploitAlso in Liquid's Bitcoin Reserves Fully Back Its Tokens Again as Board Member Points to Blockstream - Unchained, Liquid restores 1:1 BTC backing as Adam Back warns on AI fixes - Cryptopolitan