Cardano Network Temporarily Splits Following Exploited Node Bug, FBI Investigating

The Cardano blockchain temporarily split into two separate chains on November 21 following a deliberate exploit of a node validation bug, according to ecosystem organization Intersect.

The incident occurred at approximately 8:00 a.m. UTC when a developer known as Homer J exploited a vulnerability in an underlying software library, pushing through an oversized hash in a malformed delegation transaction that should have been rejected. This caused the network to diverge into two distinct chains—one containing the compromised transaction and one without it.

Cardano founder Charles Hoskinson dismissed suggestions the exploit was accidental, stating the attack "was absolutely personal" and confirming FBI involvement in the investigation. Hoskinson noted that the same exploit had been tested on Cardano's testnet just one day prior to the mainnet incident, suggesting premeditation.

While block production continued on both chains during the split, major exchanges including Coinbase paused ADA deposits and withdrawals as they monitored which chain would secure consensus. DeFi protocols and blockchain explorers briefly displayed conflicting network states.

Intersect reported that the Cardano team successfully forked and fixed the vulnerability within the same day of the incident.