On September 14, the Monero network experienced its deepest chain reorganization to date: 18 blocks were replaced, invalidating at least 118 confirmed transactions and rewriting roughly 36 minutes of network history. The reorg follows a series of similar events tied to Qubic, a mining-focused project that claims to apply “useful proof of work” by redirecting mining profits into its own token ecosystem.
Despite the severity of the reorg, Monero’s price has continued to rise. XMR is up more than 20% over the past week and over 9% on the day, briefly surpassing $320. Qubic’s token, in contrast, has lost more than 30% in the last month, though it remains above July levels.
Read also: Qubic Aims for 51% of Monero – How Serious Is the Risk?
What Happened
The reorg began at block height 3,499,659 and extended 18 blocks before the chain stabilized. Several node operators and community researchers confirmed the event using command-line tools and public blockchain explorers. The discarded branch contained over 100 confirmed transactions, most of which have since been reprocessed or returned to wallet mempools.
In Monero’s proof-of-work consensus model, short reorgs of 1–2 blocks can occur naturally. A reorg of this depth, however, is uncommon and suggests either a high concentration of mining power or intentional manipulation – most likely through selfish mining, a tactic where miners withhold blocks to later overtake the public chain.
Read also: Did Qubic Really Take Over Monero? 51% Claim Sparks Debate
Qubic Connection and Network Response
Although Qubic has not taken direct responsibility for this latest reorg, much of the community discussion has centered around its role. The project previously claimed it had gained 51% of Monero’s hashrate and has stopped publicly reporting mining stats. Unknown pools – which are believed to be associated with Qubic – remain responsible for a large portion of Monero’s block production.
Node operators and developers are now discussing temporary defenses, including the possible use of DNS-based checkpoints. These would allow nodes to fetch verified block snapshots from trusted servers, limiting the damage a reorganized chain can cause.
Looking Ahead
With Qubic still mining Monero and reorganizations growing in depth, more disruptions are possible. Community trust remains split – while some users remain committed to XMR’s long-term vision, others are worried about its reliability for payments.
Still, the market appears to be pricing in resilience. XMR continues to outperform the broader crypto sector despite repeated disruptions and growing uncertainty over future fixes.
