Add as a preferred source on GoogleBitcoin Core Discloses Flaw That Could Halt Mining After Chain Reorg
The bug affected five releases across versions 28 and 29; Bitcoin Core fixed it in October 2025, and the affected versions have since reached end of life.
Bitcoin Core disclosed a high-severity flaw that could leave a mining node unable to build block templates for Bitcoin (BTC) after a chain reorganization, disrupting block production until the node restarts.
Identified as CVE-2025-62861, the flaw affected five Bitcoin Core releases: 28.0, 28.1 and 28.2 in the 28.x series, plus 29.0 and 29.1 in 29.x.
The issue involved TRUC, or version 3, transactions. When a chain reorganization replayed transactions, Bitcoin Core failed to block the TRUC sibling-eviction mechanism. The process left the mempool in an inconsistent state.
That inconsistency caused block-template validation to fail. A block template is the candidate block the software prepares for a miner. The affected node had to be restarted before block production could resume.
Niklas Goegge responsibly disclosed the flaw. Bitcoin Core fixed it in October 2025, including in version 30.0. The affected versions have since reached end of life, so the vulnerable releases are no longer supported.
Simon Yoon
ReporterSimon Yoon reports on blockchain technology for TokenPost. Send corrections or tips to info@tokenpost.com.