Litecoin Undergoes Deep Chain Reorganization After MWEB Privacy Layer Zero-Day Exploit

Gate News message, April 26 — Litecoin experienced a deep chain reorganization on Saturday (April 26) after attackers exploited a zero-day vulnerability in its MimbleWimble Extension Block (MWEB) privacy layer, according to the Litecoin Foundation. The reorg spanned blocks 3,095,930 to 3,095,943 and took more than three hours to complete.

The bug allowed mining nodes running older software to validate invalid MWEB transactions, enabling attackers to peg coins out of the privacy extension and route them to third-party decentralized exchanges. Major mining pools were also hit by denial-of-service attacks tied to the same flaw. During the reorg, attackers performed double-spend attacks against multiple cross-chain swapping protocols that had accepted the now-orphaned MWEB peg-outs. Aurora Labs CEO Alex Shevchenko noted that exposure for NEAR Intents reached approximately $600,000. The Foundation confirmed that offending transactions were erased from Litecoin’s history while valid transactions remained unaffected, and the vulnerability has been fully patched.

Litecoin traded near $56.00 around 4:30 p.m. ET, down approximately 1% on the day with no immediate market reaction to the disclosure. The token is down nearly 25% year-to-date. Saturday’s incident marks the first known attack on MWEB since Litecoin activated the privacy extension via soft fork in May 2022, arriving amid a challenging period for crypto security; DeFi protocols have suffered over $750 million in losses to exploits through mid-April 2026.