Bitcoin Core 32.0 enters final testing ahead of October release

Bitcoin's main software is heading for a big update. Developers tagged Bitcoin Core 32.0 as a release candidate on September 14 and aim to ship the final version on October 10. It speeds up how nodes check the blockchain and fixes several security bugs.

The schedule comes from a public roadmap that Bitcoin Core maintainer fanquake posted on April 20. It set a feature freeze for August 20 and the first release candidate for September 14. The October 10 date is an aim, not a promise. Testing can push it back.

Bitcoin Core is the implementation that most full nodes on the network run. It is the software that checks every block and transaction against the rules. A new major version does not change those rules here. It changes how well the software does the job, which is why node operators and businesses track each release closely.

What the update changes under the hood

Speed is the headline change. Bitcoin Core 32.0 loads transaction data in parallel while it checks new blocks, using eight threads by default and up to sixteen. The aim is to stop slow disk reads from holding up validation, according to coverage of the draft release notes by Cointribune. The work sits close to how a Bitcoin transaction moves through the network, which every full node has to recheck for itself.

A faster node does not make Bitcoin faster for everyone. Blocks still arrive about every ten minutes. Payments do not clear any quicker. The gain lands with the people and businesses that run full nodes, who should spend less time waiting for their software to catch up with the chain.

The security bugs it closes

Bitcoin Core 32.0 also patches bugs that could have let an attacker crash or hijack a node. One turned up during AI-assisted auditing of the code. An unauthenticated connection to the software's REST interface could pile up 3.2 GB of memory in a single minute. After the fix, the same test adds about 3 MB over 90 seconds, Cointribune reported.

Another fix closes a flaw in a feature called walletnotify. On non-Windows systems, a logged-in user of the software's command interface could forge wallet names and run commands they should not. The release also swaps out an old networking library called libevent for a new HTTP server that caps how many clients can connect at once.

There is a smaller win on storage too. A rebuilt transaction index, known as txindex, uses less than half the disk space it did before, Cointribune reported. That matters most to node operators and services that keep the full index on hand to look up past transactions.

What it means for wallets and node operators

Most people who just hold Bitcoin in a wallet or on an exchange will not notice this release. The changes sit deep in the plumbing. Nothing flashy. Two groups should pay attention.

Wallet developers get a format change. Four wallet commands that build partly signed transactions will default to a newer format called PSBT version 2. Apps can still ask for the old format, so nothing breaks overnight, but builders will want to test their tools against it.

Node operators face a deadline of a different kind. Each time a new major version ships, the oldest version still being maintained drops out of support and becomes end-of-life, TFTC noted. Anyone running their own node on an older version should check which one they are on and plan to upgrade before 32.0 lands, because unmaintained software carries a security risk that grows over time.

What to watch

Watch the Bitcoin Core release page for the final 32.0 tag. The October 10 date holds only if testing turns up no fresh problems. Release candidates exist for exactly that reason. Once a version reaches this stage, developers stop adding features and merge only bug fixes.

Also watch which older version gets marked end-of-life when 32.0 ships. That is the signal for a group of node operators to upgrade. The draft release notes are not final, so some details can still change before launch.