Ethereum Classic Miners Reject Disputed Core Geth Update
Ethereum Classic (ETC) mining pool operators reversed their migration to disputed Core Geth v1.13.0 after concerns over its development process, security claims and consensus changes. Classix reported that 96 commits, adding 13,422 lines and deleting 3,977, were pushed within 56 hours without pull requests or external review.
Four 2Miners nodes briefly ran Core Geth v1.13.0 on 15 September 2026 before returning to the maintained Argos v1.12.23 client. Etcnodes.org recorded 11 v1.13.0 nodes initially, falling to 10 the next day. Classix said no blocks, funds or services were lost, and no chain reorganisation occurred.
The disputed Core Geth release re-enabled Modified Exponential Subjective Scoring (MESS), which could create different consensus behaviour between clients. It also replaced Ethereum Classic’s established peer-discovery infrastructure with a new DNS signing key and three hardcoded bootnode IP addresses.
Classix challenged the release’s claim that Ethereum Classic’s 1.12.x clients contained unpatched security flaws. It said most issues had already been fixed in Argos and earlier maintained releases, while others did not affect ETC’s active network features.
Classix advised Ethereum Classic node operators to avoid Core Geth v1.13.0, restore previous node keys if rotated and use Argos v1.12.23. It also urged greater GitHub repository controls and more client diversity across the ETC network.
Neutral
The immediate market impact is likely neutral. The Ethereum Classic incident affected a limited number of nodes, and Classix reported no lost blocks, chain reorganisations, fund losses or service interruptions. Mining operators also reversed the migration quickly, reducing the probability of an immediate trading shock.
The event still creates a short-term operational risk for ETC. Traders may monitor exchange deposits, network hash rate, block production and confirmation times for signs of client incompatibility or a wider split. If more nodes continue running the disputed client, the reactivation of MESS could produce inconsistent consensus behaviour and increase volatility. A confirmed chain reorganisation or prolonged network disruption would be bearish, but neither occurred in this incident.
In the longer term, the episode may encourage ETC miners to diversify across Besu, Nethermind, Getc and other clients. Greater client diversity could improve resilience and reduce single-client failure risk. However, the dispute may weigh on confidence in Ethereum Classic governance and development coordination. Similar to the majority attacks and reorganisations ETC experienced in August 2020, a future consensus split or security event could cause sharper ETC selling, wider spreads and reduced exchange confidence. For now, the absence of economic losses and the rapid rollback support a neutral assessment rather than a bullish or bearish signal.