While the crypto industry tries to recover from a harsh crash, other problems arise on the horizon. In an atmosphere already saturated with volatility, it’s Cardano, renowned for its stability, whose network fractured. A bug several years old, a malformed transaction, an operator a bit too curious… and suddenly, the protocol wobbles. No thefts, no loss of funds… but an already tense climate of trust cracks even more. A narrowly avoided earthquake.
The Cardano news: on November 21, 2025, the blockchain experienced a chain split caused by a malformed transaction. Behind this flaw? A discreet bug, hidden in the code since 2022, awakened by a staking operator using AI-generated code.
Homer J, the responsible party, did not shirk responsibility: “Sorry (I know that word isn’t enough given the impact of my actions) Cardano community, I endangered the network through my negligence last night. It was initially a personal challenge like “let’s see if I can reproduce the bad transaction,” and I was quite foolish… ”
Result: two chains formed. One contained the “poisoned” transaction, the other did not. Miners continued producing blocks… on both. But only one could survive.
Voices in the community quickly denounced an attack. Charles Hoskinson, founder of Cardano, does not mince words:
This was a premeditated attack carried out by a disgruntled SPO who spent months on the Fake Fred Discord actively looking for ways to harm the IOHK brand and reputation. He targeted my personal pool, causing disruption across the entire Cardano network. Every user was impacted. SPOs lost rewards. There could have been double spends. DeFi was disrupted.
Using AI to interact with a blockchain is not illegal. But it requires rigor. In this particular case, it was human carelessness that amplified the problem. Homer J admitted to relying on AI model suggestions without verifying or testing. No malice, he says. But negligence that had concrete consequences.
This is not a first in the crypto world. Bitcoin experienced a similar event in 2013. A bug between client versions 0.7 and 0.8 caused a temporary hard fork. Blocks were lost. Rewards as well. Ethereum, meanwhile, saw the birth of Ethereum Classic due to the The DAO hack in 2016.
Andrew Throuvalas, a keen observer, summarizes:
Cardano indeed crashed for the first time. Apparently, a hacker caused a network partition by exploiting a bug present in an older version of Cardano’s software. This created two chains. Blocks were produced on both sides, but one will eventually outpace the other, orphaning blocks from the malicious chain.
The lesson is clear: even the best-designed chains can falter. The goal is not infallibility. It’s the ability to react, repair, learn.
Fortunately, the Cardano machine did not stop. Blocks continued to be produced. Quickly, operators were called to update their nodes to version 10.5.3. This version rejects the faulty transaction and reunites the two chains into one. A working group was also established for data reconciliation.
But all this does not erase doubt. Part of the community questions: if such an old bug was exploitable, what about others? Krumlar, an active user, hits the mark:
You’re not a bad person. Stop this nonsense. You want to know what’s really bad? The fragile nature of Cardano, if you can break it so easily.
Cardano’s reputation relies on scientific rigor, its formal approach. Yet this incident reveals a governance flaw. Who approves patches? Who tests thoroughly? The ecosystem, though solid, shows it remains vulnerable to human error… even accidental.
And now? Cardano is betting on the Ouroboros Phalanx update to strengthen its security and prevent this kind of drift. A necessary response, but not sufficient. Because if the technology is solid, it’s the trust that will have to be rebuilt from now on.
