Cardano Experiences First Major Chain Split in Eight Years
On November 21, Cardano faced its first significant chain split after nearly eight years of operation. This disruption was caused by transactions that exploited a three-year-old bug in the Node software, temporarily dividing the $14 billion blockchain into two competing chains.
The situation unfolded around 08:00 UTC when a fraudulent delegated transaction was rejected by the older infrastructure but managed to bypass validation checks on the new node version. This resulted in an incompatible ledger state across the network. One reporter noted that this incident closely resembled a problem observed on Cardano’s testnet just a day prior, hinting that the exploit may have been tested ahead of its release on the mainnet.
According to a report from Intersect, a Cardano ecosystem organization, “It is important to note that the network was not down. During the incident, blocks continued to be generated on both chains, and at least some identical transactions appeared on both chains.”
Still, despite the network’s continued operation, major exchanges responded by halting ADA transactions to assess which chain would achieve consensus dominance. For instance, Coinbase documented that the longest interruption lasted from 12:15 UTC on November 21 to 02:10 UTC on November 22, with deposits and withdrawals suspended for about 14 hours. Other exchanges like Upbit and Kraken implemented shorter pauses for ledger validation.
During the split, block explorers froze or displayed inconsistent data. In decentralized finance (DeFi) protocols, discrepancies could arise where smart contracts operated on one chain while relevant transactions were processed on another. Normally, transaction confirmation times in Cardano are just seconds, but during the split, they extended to minutes or even faced failures due to the network issues.
The split persisted for several hours as Input Output Global (IOG), the Cardano Foundation, Intersect, and EMURGO managed an emergency response. Remarkably, the Cardano development team rolled out an emergency patch within three hours of discovering the problem, and by November 22, the network naturally converged.
Following the incident, ADA’s price fell by 16% but has since shown some recovery, currently trading around $0.41.
Developer Apologizes; Hoskinson Raises Concerns
Shortly after the event, a user on X known as “Homer J.” publicly admitted to causing the split, referring to it as a “careless” testing error and apologizing to the Cardano community. They explained, “At first it was a personal challenge to see if I could reproduce the fraudulent transaction, but I was foolish enough to rely on an AI without adequately testing it on testnet first.”
However, Cardano founder and IOG co-founder Charles Hoskinson characterized the actions as a “planned attack” and suggested on X that the matter has drawn the attention of the FBI, saying, “It’s completely personal and now he’s trying to cancel it because he knows the FBI is already involved.”
Information distributed by Intersect and Hoskinson stated that “Relevant authorities and law enforcement agencies have been notified” regarding the developer’s actions. Efforts to reach Hoskinson or IOG for further comments were unsuccessful.
Resignation in Response to Federal Involvement
Hoskinson’s remarks about federal involvement prompted one IOG employee to announce their resignation from the organization. Identified as Roman, a Plutus language developer, he expressed concerns about the legal ramifications of past simulated cyberattacks in a podcast. He noted, “I had no idea that I was at risk of being raided by the authorities for saying something mean on the internet.”
Roman emphasized that prior issues he encountered stemmed from his own insights, stating, “What’s in the computational layer was either something I discovered directly or came from my ideas,” but did not respond to requests for comment.
