Bitcoin Core Pulls v30 Binaries After ‘Fund Deletion’ Bug Discovered

Bitcoin Core has emergency-pulled download binaries for versions 30.0 and 30.1 after developers confirmed a critical bug that can permanently delete user wallets during migration. The vulnerability, which affects legacy Berkeley DB (BDB) wallets, triggered an immediate ‘stop use’ warning from the maintainers early Monday.

BTC held steady at $93,562 (+2.5%) despite the technical alarm, suggesting the market views this as a niche operational risk rather than a systemic protocol failure.

The Technical Vector: Pruning Meets Migration

The flaw resides in the cleanup logic triggered when users migrate old BDB wallets to the newer descriptor-based format. According to the disclosure, the bug executes only under a specific triangulation of conditions:

• The user is running a pruned node (to save disk space).
• The wallet file is a legacy unnamed ‘wallet.dat’.
• The wallet directory is custom-set using the -walletdir flag.

When these align, the software successfully migrates the keys but mistakenly identifies the original directory as trash data. The cleanup process then wipes the entire folder. Without an external backup (e.g., a paper seed or separate copy), the private keys are scrubbed from the disk, making fund recovery impossible.

The migration can appear to complete successfully, but the cleanup logic mistakenly deletes the entire wallet directory. Loss of access to funds is effectively guaranteed because all local wallet files are removed.

Lacie Zhang, a market analyst at Bitget Wallet, noted the severity for long-term holders running self-hosted nodes, though Shawn Odonaghue of Orbs clarified the vector primarily targets ‘very old wallet setups’ rather than modern hardware or mobile implementations.

Immediate Mitigation

The Core team has removed v30.0 and v30.1 from the official bitcoincore.org download page. Operators currently running these versions are advised to:

1. Halt all wallet migrations immediately.
2. Backup the entire .bitcoin directory before touching the software.
3. Wait for the imminent v30.2 patch before attempting any upgrades.

The bug does not affect the Bitcoin network’s consensus rules or block validation, only the local file management of the reference client.