Cardano Faces Major Disruption as Network Splits Over Software Flaw

In Brief

• Cardano suffers a network split caused by a malformed transaction and software flaw.
• ADA price drops by 7% after the disruption, contributing to a bearish market trend.
• Cardano governance focuses on improving software resilience after the incident.

Cardano recently experienced a major network disruption, triggered by a software flaw that caused a chain split. On November 21, 2025, a malformed delegation transaction exploited a bug in an older version of Cardano’s software. 

This led to two distinct chains, with one containing invalid blocks. The disruption resulted in slower block production, network instability, and a potential double-spending risk. The incident caused ADA to drop by over 7%, adding to the ongoing bearish market sentiment.

Charles Hoskinson, co-founder of Cardano, described the event as a “premeditated attack” by a disgruntled stake pool operator. This individual had allegedly spent months plotting to damage Cardano’s reputation. 

As nodes running outdated software rejected the malformed transaction, users on both chains experienced slower confirmation times. Some exchanges, including Upbit, temporarily halted ADA transactions to prevent further risk. Despite the recovery, the event has impacted the network’s reputation and highlighted the vulnerability of blockchain systems to software flaws.

Market Impact and Cardano’s Response to the Incident

The Cardano incident had a significant impact on the ADA token, contributing to a sharp price drop. Over the past week, ADA has fallen by 21.04%, and the token is currently priced at $0.4053. 

Although ADA saw a slight increase of 1.18% in the past hour, the market remains cautious. Following the disruption, the Cardano governance organisation, Intersect, published an incident report. The report emphasised the need for improved software testing and resilience.

While network performance has already begun to recover, the event has highlighted the importance of maintaining strong security and software reliability. Moving forward, Cardano’s community is focused on enhancing the network to prevent similar issues. The incident also serves as a reminder of the challenges faced by blockchain networks in maintaining uptime and user trust.