Share this article
Bitcoin Miner Marathon Confirms Mining Invalid BTC Block Due to a Bug
The block was invalidated due to a "transaction ordering issue."
Updated Sep 28, 2023, 3:15 p.m. Published Sep 27, 2023, 11:12 a.m.
Bitcoin mining company Marathon Digital (MARA) has mined an invalid Bitcoin block at height 809478, according to several developers, miners and researchers.
The miner confirmed the mining of the invalid block on social media platform X (formerly Twitter), citing a bug during an experiment. "We utilize a small portion of our hash rate to experiment with our development pool and research potential methods to optimize our operations," Marathon said. "The error was the result of an unanticipated bug that came from one of our experiments," the company added.
STORY CONTINUES BELOW
Don't miss another story.Subscribe to the Crypto Daybook Americas Newsletter today. See all newsletters
Earlier Wednesday, anonymous Bitcoin developer "0xB10C" wrote on X that MaraPool had a "transaction ordering issue," which was confirmed by CasaHODL co-founder Jameson Lopp.
Now @MarathonDH mined an invalid block at 809478 on mainnet. I observed the block on 9 out of 9 nodes.
— 0xB10C (@0xB10C) September 27, 2023
ERROR: ConnectTip: ConnectBlock 000000000000000000006840568a01091022093a176d12a1e8e5e261e4f11853 failed, bad-txns-inputs-missingorspent, CheckTxInputs: inputs missing/spent https://t.co/SoIfTl1CXe pic.twitter.com/VeqGZjCVhK
The invalid Bitcoin block was rejected by other node operators. The block contained a transaction that was ordered incorrectly with a spending output transaction, thus, the block was invalidated, according to BitMEX Research.
The mining of invalid block raised some questions within the community as to the security of the network. However, the rejection of the block was cited by Marathon as an example of the resilience of the Bitcoin network.
"In no way was this experiment an attempt to alter Bitcoin Core in any way," the miner said, adding that the incident was unintended but "underscores the robust security of the Bitcoin network, which rejected and rectified the anomaly."
The miner's shares were down nearly 2% on Wednesday, while peer Riot Platform (RIOT) was down about 0.7%, and bitcoin price was mostly positive.
UPDATE: (Sept. 27, 16:56 UTC): Updates throughout to add confirmation by Marathon and comments from the company.
More For You
What to know:
- As of October 2025, GoPlus has generated $4.7M in total revenue across its product lines. The GoPlus App is the primary revenue driver, contributing $2.5M (approx. 53%), followed by the SafeToken Protocol at $1.7M.
- GoPlus Intelligence's Token Security API averaged 717 million monthly calls year-to-date in 2025 , with a peak of nearly 1 billion calls in February 2025. Total blockchain-level requests, including transaction simulations, averaged an additional 350 million per month.
- Since its January 2025 launch , the $GPS token has registered over $5B in total spot volume and $10B in derivatives volume in 2025. Monthly spot volume peaked in March 2025 at over $1.1B , while derivatives volume peaked the same month at over $4B.
More For You
Pye Finance Raises $5M Seed Round Led by Variant and Coinbase Ventures
The platform aims to make locked Solana staking positions tradable via an onchain marketplace.
What to know:
- Pye Finance raised a $5 million seed round led by Variant and Coinbase Ventures, with participation from Solana Labs, Nascent and Gemini.
- The startup is building an onchain marketplace on Solana for time-locked staking positions that can be traded.
- Pye says the product targets Solana’s large pool of staked SOL, worth roughly $75 billion, and aims to give validators and stakers more flexibility over terms and reward flows.
Top Stories
