Bitcoin Core Pulls v30 Release After Migration Bug Threatens to Wipe Wallets

The vulnerability, which affects versions 30.0 and 30.1, lies in the software’s wallet migration tool. Under specific conditions, the flaw causes the software to delete the entire wallet directory, including the private keys required to access funds, rather than safely upgrading the file format.

The "Pruning" trigger

The issue specifically targets older, "legacy" wallets that have not yet been updated to the modern descriptor format.

According to the disclosure, the bug is triggered when a user attempts to migrate a legacy wallet.dat file while running a node with "pruning" enabled, a setting used to save disk space by discarding old blockchain data. When these two conditions meet, the cleanup logic in the migration tool misidentifies the wallet files as disposable data and scrubs them from the disk.

"In this scenario, the migration appears to complete successfully, but the cleanup logic incorrectly deletes the entire wallet directory," noted Bitget wallet market analyst Lacie Zhang.

Binaries Removed

The severity of the bug prompted an immediate recall. Binaries for v30.0 and v30.1 have been removed from the official Bitcoin Core download page to prevent further installations.

While the bug requires a specific set of circumstances to trigger, the risk profile is highest for long-term users ("OGs") and early adopters who are most likely to be still using legacy wallet.dat files created years ago.

Fix To Be Released

Developers are currently merging a fix that will be released as Bitcoin Core v30.2.

In the interim, the project has advised users to remain on older stable versions (such as v28.x) and has issued a strict warning not to use the migratewallet tool until the patched version is live. Users who have not attempted to migrate their legacy wallets remain unaffected and can continue to run their nodes normally.