The Bitcoin Core crew alerted on January 5 a few crucial error within the pockets migration course of current in variations 30.0 and 30.1 of the software program.
In accordance with what was defined, “underneath uncommon circumstances”, when attempting to transform a legacy pockets (outdated wallets saved within the Berkeley DB format) the failure could cause the deletion of all pockets information hosted on the identical node.
If there are not any backup copies, this would carry a direct threat of lack of funds. The event crew really useful not executing mentioned migration course of till the publication of a brand new corrected model of Bitcoin Core, on this case, similar to 30.2.
The incident happens after a 12 months of robust debate within the bitcoiner group round Bitcoin Core v30, a model that, amongst different adjustments, expanded using the OP_RETURN opcode to embed arbitrary knowledge in transactions, a call that generated controversy throughout 2025.
The bug in Bitcoin Core v30 solely impacts the migration of outdated wallets
Legacy pockets migration is the mechanism by which an outdated pockets is transformed to the extra trendy format utilized by Bitcoin Core.
He bug It doesn’t have an effect on the final functioning of the node or the day by day use of present wallets; solely impacts the act of migrating legacy wallets utilizing v30.0 or v30.1.
Bitcoin Core clarified that every one different makes use of stay intact: you’ll be able to proceed working a node, use present wallets, and function as regular. The repair will arrive with Bitcoin Core 30.2. Till then, the advice is to not migrate legacy wallets with 30.0/30.1.
As a further measure, the binaries (set up executable information) v30.0 and v30.1 have been labeled “unsafe”. On the official website, the really useful obtain was as soon as once more Bitcoin Core 28.1, a earlier model thought of secure, and which doesn’t embrace the elimination of the OP_RETURN restrict.
Reactions and criticism from the group
Bitcoiner developer Tomer Strolight referred to as the problem harshly:
That is fairly severe if I am studying it appropriately. If you’re attempting emigrate a legacy pockets, Bitcoin Core 30.x could delete all wallets on the system. In fact, backups ought to all the time be maintained, but it surely’s so extreme that Core eliminated v30.x as a really useful model on their very own website.
Tomer Strolight, bitcoiner developer.
Strolight added that given the earlier emphasis on putting in v30 for supposed safety enhancements, there must be intensive and proactive communication about this bug: “Those that promoted its set up ought to increase widespread alerts earlier than somebody loses all their pockets information.”
The episode highlights two key factors. First, the significance of backups: A pockets and not using a backup all the time implies threat.
Second, even in crucial and audited software program errors can come up with severe penalties. The crew’s response (public alert, binary elimination, and a scheduled patch) goals to comprise the affect.
Till the publication of Bitcoin Core 30.2, the steerage is evident: don’t migrate legacy wallets with v30, hold backups and, if a secure set up is required, go for 28.1.
