Bitcoin Core 32.0 entered release-candidate testing on Monday, with developers targeting October 10 for the final release. The software update is designed to improve performance and address security flaws in the system that allows users to independently verify Bitcoin transactions and blocks.
The update primarily affects node operators and developers who use Bitcoin Core to run wallets and other services. According to draft release notes, the software can speed up block verification by reading database information in parallel, without changing Bitcoin's block production rate.
Transaction Format Changes
Four wallet commands will default to a newer format for exchanging partially signed transactions between wallets and signing devices. Applications can still request the older version if needed.
Security Fixes
The update addresses two main security issues. A fix prevents crafted wallet names from triggering unauthorized commands on a node's computer. This vulnerability affected non-Windows systems where authenticated users could create wallets with the walletnotify feature configured to run commands during wallet transactions.
A separate patch resolves excessive memory consumption in Bitcoin Core's new HTTP server, which handles requests from connected applications. Contributor Matthew Zipkin discovered an out-of-memory condition while auditing the HTTP server with an AI model. An earlier fix had addressed part of the problem, but a method to exhaust available memory remained.
During patch review, another developer found that unauthenticated requests could also cause memory growth when the REST interface was enabled. After revision, testing showed 16 unauthenticated connections caused approximately 3 MB of memory growth over 90 seconds, compared with 3.2 GB before the fix.
The patch was merged on September 5 as part of ongoing security improvements to Bitcoin Core.
