Litecoin Undergoes 13-Block Reorg After Zero-Day Vulnerability Exploit

What Happened on the Litecoin Network

The Litecoin network experienced a significant security incident on April 25 when attackers exploited a zero-day vulnerability, triggering a deep blockchain reorganization. The attack began with a denial-of-service assault that knocked major mining pools offline, then leveraged nodes running outdated software to validate fraudulent transactions.

The Litecoin team addressed the situation publicly:

«Litecoin update: • A zero-day bug caused a DoS attack that disrupted major mining pools. • Non-updated mining nodes allowed an invalid MWEB transaction allowing them to peg out coins to third party DEX's • A 13-block reorg reversed those invalid transactions — they will not…» — Litecoin (@litecoin), original post

Why This Matters

A 13-block reorganization is an exceptionally rare event for a major proof-of-work blockchain. This incident raises questions about the resilience of the network against coordinated attacks and the security of the MimbleWimble Extension Block (MWEB) privacy feature. The fact that attackers were able to execute double-spend attacks against multiple cross-chain protocols during the reorg window highlights the cascading risks that blockchain reorganizations pose to the broader DeFi ecosystem.

Attack Breakdown and Developer Response

According to the incident report, the attack unfolded in stages. First, the attackers launched a DoS attack that disrupted major mining pools. With those pools hampered, nodes that had not been updated to the latest software version began confirming invalid MWEB-layer transactions. This allowed the attackers to interact with illegitimate coins and send them to third-party decentralized exchanges.

To counter the exploit, developers executed a 13-block reorganization that reversed all invalid transactions and removed them from the canonical chain. Litecoin representatives stated that all legitimate transactions during the affected period were preserved, the bug has been fully patched, and the network is operating normally.

Alex Shevchenko Calls It a "Coordinated Attack"

Aurora Labs CEO Alex Shevchenko described the incident as a "coordinated attack." According to his analysis, the reorganization affected blocks #3,095,930 through #3,095,943 and took over three hours to resolve. During that window, the attackers carried out double-spend attacks against several cross-chain protocols.

Litecoin representatives confirmed: «All valid operations during this period remained unchanged. The bug has been fully fixed, and the network continues to operate normally.»

Minimal Impact on LTC Price

Despite the severity of the incident, market reaction was muted. At the time of reporting, LTC was trading around $56, down just 0.5% over 24 hours.

For context, a similar event occurred in September 2025 when Monero experienced its largest blockchain reorganization in 12 years — an 18-block rollback that invalidated 117 transactions.