Litecoin confirmed a zero-day bug led to a 13-block chain reorganization on April 25, 2026, following a denial-of-service attack on major mining pools. The bug allowed invalid MimbleWimble Extension Block (MWEB) transactions via non-updated nodes, which were reversed by the reorg before settling on the main chain. Litecoin assured that all valid transactions remain unaffected and the bug has been fully patched.The incident, initially mistaken for a 51% attack, was clarified by Litecoin as a corrective measure against the exploit. NEAR Intents reported $600,000 in exposure but actual losses may be lower as invalid transactions were wiped. The event underscores vulnerabilities in proof-of-work networks with outdated nodes, prompting cross-chain protocols to reassess their exposure.