- A malicious transaction caused a temporary fork on Cardano, but engineers contained the issue within hours.
- No user funds were lost, though some validators missed block rewards; the FBI is now involved.
- The attacker apologized publicly, and the Midnight (NIGHT) token launch is still set for December 8, 2025.
Cardano had a chaotic moment on November 21, 2025, when a maliciously crafted transaction slipped past normal validation checks and briefly split the blockchain into two. For a few hours, parts of the network were operating on different chains—a situation that could’ve turned ugly if it dragged on. But engineers from Input Output, the Cardano Foundation, and Intersect jumped into an emergency “war room,” patched the issue, and pushed out fixes in record time.
Charles Hoskinson later praised the teams, noting that the attacker had been preparing the exploit for months, yet Cardano contained it within a day. “This shows how strong our system is, even in unexpected conditions,” he said. The root cause was traced to a bug buried deep in a software library that was exploited by the rogue transaction.
No user funds lost, though validators took a hit
Even though the incident caused a temporary network fork, retail users’ funds stayed safe. Most wallets rely on node components that weren’t affected by the bug, so average users barely felt a ripple. Validators, however, weren’t as lucky. Some missed out on block rewards during the disruption, and Hoskinson admitted it will take weeks to restore validator rewards across the affected pools.
He also revealed that the attacker specifically targeted his personal stake pool—something that amplified the chaos across the network. Authorities quickly got involved. Intersect confirmed the attack is now classified as a cybercrime, and the FBI has begun a formal investigation.
Attacker identified, apologizes publicly, and admits acting alone
After tracking the wallet tied to the invalid transaction, Intersect managed to identify the person behind the exploit. In a twist nobody expected, the attacker actually went public with an apology on X. He claimed he acted alone, didn’t short ADA, and didn’t intend to profit from the situation. He framed it as a mistake—an “I messed up” moment—while accepting full responsibility.
Hoskinson wasn’t impressed. He called the incident a case of “carelessness” and made it clear that consequences are coming. Still, he emphasized that Cardano’s ability to recover so quickly is proof of the network’s resilience.
Midnight token launch remains on schedule
Despite the attack, the Cardano ecosystem is still moving ahead with its next big milestone: the launch of Midnight’s native token, NIGHT, set for December 8, 2025. Hoskinson confirmed during The Midnight Summit that the rollout is on track, unaffected by the disruption.
Engineers are now prioritizing improvements to the node software and broader network infrastructure to prevent similar exploits from slipping through again. Hoskinson remains upbeat about the long-term roadmap, saying stronger security upgrades are already underway.
