Monero Suffers 51% Attack, Raising Security Concerns in Crypto & XMR Community

Monero (XMR), the renowned privacy-focused cryptocurrency, is currently under a significant security threat. Charles Guillemet, Chief Technology Officer at Ledger wallet, has confirmed that Monero is experiencing a successful 51% attack — a highly concerning event where a smaller blockchain network is effectively taking control of one of the largest privacy coins.

What Happened in the Monero Attack?

In a recent tweet, Ledger CTO Charles Guillemet revealed that the Monero network is undergoing a 51% attack orchestrated by the mining pool of a smaller blockchain called Qubic. Qubic, currently ranked 222nd on CoinMarketCap with a market capitalization just under $300 million, has gradually increased its mining power. Now, it has seized majority control of the Monero network, which boasts a market cap exceeding $6 billion.

This scenario is particularly alarming because it means a smaller chain is overtaking a much larger and more established one. Guillemet described the attack as “successful” and pointed out that a major blockchain reorganization has already been detected, signaling Qubic’s dominance in mining Monero blocks.

The Implications of the Monero Attack

A 51% attack allows the controlling entity — in this case, Qubic — to rewrite Monero’s blockchain history, enabling double-spending and transaction censorship. According to Guillemet, the consequences of this takeover include:

Blockchain Reorganization: Qubic’s miners can reverse recent transactions, disrupting the network’s transaction history.
Double-Spending: Attackers can spend the same XMR coins multiple times, severely undermining trust.
Censorship: Qubic could block or delay transactions, controlling which transactions are included in the blockchain.

The cost to maintain this daily attack is estimated to be around $75 million, an amount Qubic appears willing to invest to assert control. This substantial financial commitment threatens the network’s integrity overnight, potentially leaving other miners discouraged due to the loss of incentives. Guillemet warns that Qubic could become the sole Monero miner if this situation persists.

Why Monero?

Launched in 2014, Monero is among the top privacy coins globally, focusing on secure and untraceable transactions. However, its strong privacy features have resulted in bans from many major centralized exchanges, limiting liquidity and exposure.

Despite these challenges, Monero has maintained a sizable community and network. The ongoing Monero attack represents a critical threat that could severely damage the network’s reputation and operational security.

Market Reaction and Future Outlook

Following the announcement of the attack, Monero’s price dropped by approximately 13%, reflecting market concerns over its security and long-term viability. The attack risks shaking investor confidence and could lead to a decline in network participation, which would further weaken Monero’s defenses.

Guillemet stressed that Monero’s options for recovery are limited, noting: “A full takeover is now possible and even likely.” The development community faces the urgent task of responding to this threat to prevent Qubic from gaining permanent control.

What Can the Monero Community Do?

To mitigate the damage from the ongoing Monero attack, the community and developers may consider the following steps:

Increasing Network Decentralization: Encouraging more diverse mining participation to dilute any single entity’s influence.
Consensus Algorithm Updates: Exploring technical changes to resist 51% attacks more effectively.
Enhanced Monitoring: Deploying advanced tools to detect and respond rapidly to suspicious mining activity.

Until these measures are implemented, Monero holders should remain cautious, monitor official channels for updates, and avoid large transactions to minimize risks.

Conclusion

The current Monero attack highlights a critical vulnerability in even the most privacy-focused blockchains. The takeover by a smaller, $300 million chain threatens to disrupt Monero’s $6 billion ecosystem, putting user funds and transaction integrity at risk.

As Ledger CTO Charles Guillemet warns, the stakes are high. The crypto community will be watching closely to see how Monero responds to this unprecedented challenge and whether it can safeguard its network from full control by Qubic.