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Cardano Restores Network After Malformed Transaction Causes Chain Partition

Cardano Restores Network After Malformed Transaction Causes Chain Partition

A corrupted transaction targeting founder Charles Hoskinson’s stake pool split Cardano’s network for hours, prompting emergency fixes and debate over whether it was reckless experimentation or deliberate sabotage.

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Fact Check
The assessment is 'likely_true' with high confidence, based on strong and consistent evidence across all provided sources. The highest authority source, an official incident report from Intersect, directly confirms every element of the statement. It explicitly identifies a “'malformed delegation' transaction” as the root cause of the chain partition and details the resolution strategy. This primary account is directly corroborated by multiple reputable news sources, including Crypto Briefing and CryptoRank, which also report that a malformed transaction triggered the event and that the network subsequently recovered. Sources that mention a “code bug” are not contradictory; a malformed transaction is the vector that exploits such a bug. The consensus across all sources, particularly the definitive primary source, is unanimous, and there is no conflicting evidence provided.
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Summary

Cardano’s network was disrupted for several hours on November 21, 2025, after a malformed transaction targeted Charles Hoskinson’s personal stake pool, exploiting a 2022 cryptographic library bug. The bug caused newer nodes to accept the transaction while older nodes rejected it, triggering a chain split that halted block production and impacted validators, DeFi protocols, and dApps. The responsible stake pool operator claimed it was an ill-judged personal challenge using AI-generated instructions, denying financial motives or intent to harm. Hoskinson disputed this, alleging premeditated sabotage tied to hostile online groups. Law enforcement is now involved. While user funds remained safe, the event caused missed rewards, stalled applications, and exposed vulnerabilities in Cardano’s protocol handling of malformed transactions.

Terms & Concepts
  • Chain Split: A temporary divergence in a blockchain’s ledger where different nodes follow separate branches, disrupting consensus.
  • Malformed Transaction: A transaction with improperly structured or invalid data that can trigger processing errors in blockchain nodes.
  • Cryptographic Library Bug: A flaw in a cryptography-based software component that may cause incorrect data validation or security vulnerabilities.