- Older wallets risk being deleted during the Bitcoin Core v30 migration.
- Back up your wallet and data directories before attempting an upgrade.
- Modern wallets and hardware wallets remain largely unaffected.
A critical bug has been discovered in Bitcoin Core v30, prompting concern among users planning to upgrade their wallets.
The issue specifically affects the wallet migration process, which is intended to move older wallets to the latest software version.
Under certain conditions, this migration can delete wallet files, putting users’ funds at risk.
Developers have confirmed that the bug primarily impacts older legacy wallets, especially those that have not been renamed or updated in many years.
Official sources indicate that modern wallets and hardware wallets are largely not affected.
However, the risk remains significant for anyone running a node with outdated wallet files who attempts a migration.
Bitcoin Core wallet bug
The problem occurs when Bitcoin Core attempts to migrate a nameless legacy wallet located in a custom wallet directory.
If pruning is enabled, the software can misinterpret the migration process and unintentionally delete all files in the wallet directory.
This is not a network-level bug, so the Bitcoin blockchain itself remains secure.
Instead, the threat is local: users can lose access to their funds if no external backup exists.
The vulnerability is triggered only during migration attempts.
Simply running the software or syncing the blockchain is not enough to cause file deletion.
Developers responded quickly by removing the v30.0 and v30.1 binaries from the official download page.
Users are now urged to avoid performing any wallet migrations until a fixed release is available.
Steps users should take
The Bitcoin Core v30 bug is serious but avoidable, provided users follow official guidelines and prioritize backups.
Bitcoin Core recommends backing up the entire wallet and data directories before attempting an upgrade.
This precaution can prevent potential loss, especially for users with older wallets.
It is also advised to confirm whether a wallet is classified as “legacy” or “modern.”
Those with older installations should exercise extra caution when handling migration procedures.
Users should also verify their directory configurations, including the -walletdir parameter, to ensure files are not accidentally removed.
Keeping offline or external backups remains the safest way to protect funds.
Although the bug does not compromise the network, the risk to individual wallets is real and immediate.
The community is awaiting the release of Bitcoin Core v30.2, which will fix the migration bug and restore safe upgrade procedures.
Until then, cautious users are strongly advised to pause all wallet migrations and store backups externally.
The discovery of this bug serves as a reminder that software updates, while necessary for security and performance, can introduce unforeseen risks for legacy systems.
By taking straightforward precautions, users can avoid potential losses and ensure their Bitcoin holdings remain secure.