Cryptocurrency developer Sergey Ivancheglo, known in the community as ‘Come-from-Beyond’ (CFB), has raised concerns about Qubic gaining control over a significant portion of Monero’s mining power. With Qubic controlling over 51% of the network’s hash rate, other miners are facing diminished opportunities and potential challenges to their operations. Charles Guillemet, CTO of Ledger, highlighted these concerns, estimating that Qubic’s dominance could lead to various issues like blocking competing blocks, altering the chain, or even enabling double-spending attacks. 51% control represents a significant power imbalance, potentially posing significant security threats to Monero.