Bitcoin Core 32 enters final testing with faster validation, fee changes and security fixes

Bitcoin Core 32.0 entered its final testing phase on Sept. 14, with a target stable release of Oct. 10. The update brings a new fee estimator that considers unconfirmed transactions, faster block processing via multi-threaded database access, default use of PSBT v2 for some wallet commands, and security fixes for a wallet command-execution flaw and a memory-exhaustion issue in a new web server.

By AI NewsroomPublished about 1 hour agoUpdated about 1 hour ago0 views

Bitcoin Core 32 enters final testing with faster validation, fee changes and security fixes

Why It Matters

These changes aim to improve transaction fee accuracy and node synchronization speed while addressing vulnerabilities that could allow command execution or crash a node, affecting operators who run wallets or expose REST endpoints. Fixes identified before the stable release help reduce risks for services and tools built on Bitcoin Core.

Key Facts

Release candidate tagged: Sept. 14, 2026
Planned stable release date: Oct. 10, 2026
Consensus rules: No changes to Bitcoin's consensus rules in version 32.0
New fee estimator: Adds an estimator that evaluates transactions waiting for confirmation
Block processing threads: Nodes will use 8 threads by default to fetch transaction data during block validation

Bitcoin Core 32.0 moved into final testing on Sept. 14 with developers aiming to ship a finished release on Oct. 10. The update keeps Bitcoin's consensus rules unchanged but introduces several operational and wallet-related improvements intended to speed up node catch-up and improve transaction building.

One notable change is a second fee estimator that looks at transactions currently waiting in the mempool rather than relying only on fees paid by transactions already included in prior blocks. The software will compare the two estimators and may recommend the lower fee when current network conditions allow, which should let suggested fees fall more quickly after congestion eases.

To reduce time spent waiting on disk during block validation, Core can now fetch transaction data from its databases using multiple processing threads; the client will use eight threads by default. Wallet behavior was also adjusted: four commands that create partially signed Bitcoin transactions (PSBTs) will default to PSBT version 2, though applications can still request the older format if needed.

Developers fixed a command-execution vulnerability affecting non-Windows systems that had been present since Bitcoin Core 24.0. In configurations where an authenticated user could create wallets and the operator had enabled walletnotify, a specially crafted wallet name could previously be interpreted in a way that led to command execution. Version 32 treats wallet names as literal text to block that vector.

An audit of a new web server component, performed using Moonshot AI’s Kimi K3 model, uncovered a memory-exhaustion problem where a client could continue sending data while prior requests were processed, allowing memory to grow until it was exhausted. Tests showed 16 unauthenticated REST connections could raise a node’s memory use from about 46 MB to roughly 3 GB in about a minute; a 90-second test reached 3.2 GB before the fix and about 3 MB after. The new server has not been included in a stable release, and the issue was addressed prior to shipping version 32.0.