Bitcoin Core fixes hidden privacy risk before next major release

Bitcoin Core has released version 31.1rc1, fixing a privacy flaw in PrivateBroadcast while introducing software, wallet, and validation improvements ahead of the next stable mainnet release.

According to the Bitcoin Core development team, version 31.1rc1 is now available as a release candidate, giving users, node operators, and developers an opportunity to test nearly finished software before the official production release. The developers said the testing period is intended to uncover any remaining issues that may not have appeared during internal development.

The most notable change addresses a privacy issue affecting the PrivateBroadcast feature. According to the release notes, certain network conditions could expose a user’s internet address by allowing a connection outside the intended privacy network. The updated software removes that behavior, making transaction broadcasting more consistent for users who rely on privacy-focused network configurations.

Privacy protections and node performance receive upgrades

Alongside the privacy fix, the Bitcoin Core developers introduced several changes to improve blockchain validation and long-term node performance. According to the project documentation, the software now manages transaction-related data more efficiently while maintaining a leaner blockchain database, a change designed to reduce unnecessary storage growth and improve performance as the chain expands.

Networking behavior has also been refined. The developers said Bitcoin Core now handles proxy settings and PrivateBroadcast connections more intelligently, providing more predictable behavior for users routing traffic through privacy tools such as proxy networks.

Wallet functionality received additional maintenance updates as well. According to the release notes, migration checks have been improved, and transaction input size estimation has been refined, allowing wallet operations to calculate transaction data more accurately behind the scenes without changing the user experience.

Security improvements extend to signatures and developer tools

Security-related updates also include additional safeguards for MuSig2, the signature aggregation protocol supported by Bitcoin Core. According to the developers, the software now rejects empty public key lists that contain invalid public keys, preventing incorrect signature aggregation and improving validation during multi-signature operations.

Several changes were introduced for developers maintaining or building software around Bitcoin Core. The release notes state that testing utilities have been cleaned up, race conditions have been removed, fuzz testing has been expanded, and build systems have been updated to improve software reliability during development.

Configuration handling has also been strengthened. Before saving important settings, Bitcoin Core now performs checks for failed write operations, a safeguard the developers said can help prevent configuration errors caused by unsuccessful disk writes.

Version 31.1rc1 is available for current versions of Linux, macOS, and Windows. According to the Bitcoin Core team, users running recent software versions can upgrade directly, although systems upgrading from much older releases may require additional time to migrate existing blockchain data.

Because version 31.1rc1 remains a release candidate rather than the final production version, the developers are encouraging the community to install the software in test environments, verify its behavior under real-world conditions, and report any bugs before the stable release reaches the Bitcoin network. The project said feedback collected during this testing phase will help identify remaining issues before the software is finalized.