Cardano Suffers First Chain Split Since 2017 After Node Vulnerability Exploited

Cardano experienced its first chain split on November 21, 2025, when a malformed delegation transaction exploited a three-year-old bug in node software, causing two competing chains to run simultaneously on the $14 billion network. Multiple exchanges suspended ADA deposits and withdrawals for up to 14 hours as the incident unfolded. Block production continued on both chains throughout the disruption, with emergency coordination among ecosystem stakeholders resulting in patch releases within three hours and network reconvergence by November 22.