Litecoin had to eat its own insults about Solana’s downtime

For two years, Litecoin’s social media managers laughed at Solana’s blockchain outages. This weekend, they had to eat their own words as Litecoin’s blockchain suffered its own denial-of-service and double-spending attack.

Repeated Solana outages drew smug chuckles from Litecoin. Unlike Solana, according to its sustained declarations, Litecoin doesn’t have outages.

On Saturday, that talking point died. Litecoin definitely had an outage, as well as a double-spending problem.

A consensus bug in Litecoin’s privacy upgrade let an attacker mint invalid coins. Looking to double-spend as quickly as possible, the attacker rapidly traded LTC for other digital assets at crypto exchanges before honest miners could stop the sales.

Its blockchain split. Eventually, miners rolled-back transactions, creating about 32 minutes of de facto downtime.

Interestingly, due to the unusually slow mining times during the attack, it actually took over three hours in real-time for the network to produce the 13 replacement blocks that would have normally consisted of just 32 minutes worth of transactions.

Anyway, the Litecoin Foundation then explained its 13-block reorganization to its own followers.

No more 100% uptime

Just weeks earlier, Litecoin boasted of its “100% uptime,” claiming its blockchain “100% works” after being “100% battle-tested.”

Litecoin’s account spent 2024 and 2025 laughing at Solana’s problems without fixing its own.

When Solana scheduled maintenance for a weekend in June 2025, Litecoin told the Solana account, “This way you can schedule your outages for the weekends. Good call.”

It replied to another Solana status update with one word, “Downtime.” 

When the two networks signed a tongue-in-cheek ceasefire later that month, the foundation’s joke version had Litecoin promising to stop “mocking Solana for six hours and Solana will just continue to not do anything.”

Solana’s own people declined to return the favor this weekend. Vibhu Norby, Solana Foundation’s interim chief product officer posted, “I will not bring up the 1,000 times @litecoin dunked on Solana for downtime. Because we are better than this.”

Read more: CHART: It’s been 262 days since Solana’s last major outage

Litecoin and Solana downtimes

The Litecoin vulnerability lived in MWEB, Litecoin’s Mimblewimble-based confidential transaction extension. Aurora Labs CEO Alex Shevchenko, whose chain ingests LTC via NEAR Intents, documented the exploit in real time. 

The attacker submitted a malformed MWEB peg-out. Non-upgraded Litecoin mining nodes accepted it as valid, releasing synthetic coins into the regular Litecoin blockchain. 

The attacker then bridged the proceeds through THORChain and NEAR Intents to swap for ether.

Honest miners running the patched 0.21.5.4 client rejected the attacker’s blocks. From there, the two forks raced. 

After several hours, the patched chain eventually won heavier proof-of-work and the network re-organized blocks 3,095,930 through 3,095,943 out of existence. 

Although the reversed transaction time window was only 32 minutes, it took nearly three hours to actually reverse those minutes, because hashpower was split between honest and exploited nodes.

The patch was on GitHub for a month

Dragonfly Managing Partner Haseeb Qureshi noted that the Litecoin double-spending bug was “known, but the fix was not fully propagated.” 

Indeed, the underlying consensus fix had sat in a private GitHub branch for about 30 days.

A security researcher questioned that asymmetric disclosure window, which gave insiders a month-long head start. Several major mining pools, apparently, never installed the public release in time.

For non-insiders, the public Litecoin Core 0.21.5.4 release shipped on Saturday, shortly after the attack had begun.

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