June 1, 2020 Bitcoin developer discovers a bug in timelocked Bitcoin transactions.

A pseudonymous German Bitcoin developer by the name of 0xB10C, detailed a bug in timelocked Bitcoin transactions through his blog, published in April this year. The developer found that 1.16 million timelocked transactions from September 2019-March 2020 were not enforced, representing 10% of timelocked transactions in that period, which themselves accounted for 19% of total network transactions. Such transactions are designed to prevent fee-sniping from miners by making such activity less profitable. While miners apparently do not currently engage in fee-sniping, it could enable chain reorganizations in the future once transaction fees become a larger portion of miner revenue. 0xB10C explained that a fix has already been released but that it will take some time for all installations of the current software to be upgraded.

Sources: