Litecoin faces double-spending attack and MWEB failure.

• Litecoin suffers double spending attack via MWEB
• Zero-day failure causes LTC blockchain reorganization.
• Cryptocurrency security under pressure in 2026

The Litecoin network underwent a significant reorganization last Saturday after the exploitation of a zero-day vulnerability linked to the MimbleWimble Extension Block (MWEB) privacy feature. The issue affected transaction validation and opened the door for fraudulent operations involving double spending.

According to the Litecoin Foundation, the vulnerability allowed outdated mining nodes to accept an invalid transaction within the MWEB. This allowed malicious actors to decouple coins from the private layer and redirect them to external platforms, including decentralized protocols.

Furthermore, mining pools faced denial-of-service attacks related to the same flaw, amplifying the impact of the incident. Aurora Labs CEO Alex Shevchenko described the event as a “coordinated attack” and detailed that the fork occurred between blocks 3.095.930 and 3.095.943.

According to him, the production of these blocks took more than three hours, during which time double-spending attacks were executed against protocols that accepted transactions that were subsequently invalidated. “NEAR Intents’ exposure is around US$600,” he stated. “We recommend that all LTC trading platforms audit transactions and holdings. We observed many double-spending transactions.”

The Foundation reported that all problematic transactions have been removed from the blockchain history, while legitimate operations have been preserved. The vulnerability has already been fixed, although some platforms have reported losses.

MWEB, implemented in May 2022, allows transfers between the main chain and a confidential layer. The exploited vulnerability compromised precisely the mechanism responsible for ensuring the integrity of these transactions.

During the incident, the price of Litecoin was trading near US$56, down about 1% on the day, with no immediate market reaction. Year-to-date, the asset has registered a decline of approximately 25%.

This incident occurs amidst a series of attacks in the sector. DeFi protocols have already lost more than US$750 million this year, notably due to vulnerabilities involving cross-chain solutions, the same vulnerability exploited in this episode involving Litecoin.