Bitcoin Core v30 has a vulnerability that may cause fund loss when upgrading from an older wallet version

According to market news, Bitcoin Core developers have warned users that versions 30 and 30.1 contain a wallet migration vulnerability that may delete files and lead to loss of funds. This issue occurs only under specific conditions and affects the migration of old Bitcoin Core wallets that have never been renamed or upgraded.

Bitget wallet market analyst Lacie Zhang stated that the vulnerability is triggered when the software attempts to migrate unnamed old "wallet.dat" files stored in a custom wallet directory (usually defined by the "-walletdir" setting) while the pruning feature is enabled. In this case, the migration appears to be successfully completed, but the cleanup logic incorrectly deletes the entire wallet directory. Shawn Odonaghue, head of the Orbs community, mentioned that the vulnerability mainly affects "very old wallet setups," and users with hardware wallets or modern wallet software are unlikely to encounter such issues.

Bitcoin Core version 30.1 was released on January 1, and the wallet migration vulnerability was publicly disclosed on Monday. Developers have withdrawn the binaries for versions 30 and 30.1 from the official download site. The project advises users not to use the wallet migration tool until the fixed version Bitcoin Core 30.2 is released and emphasizes that existing users who have not attempted migration can continue to run their nodes normally.