MultiversX Halted After Atomicity Exploit

MultiversX has halted its mainnet to address an attempted virtual-machine exploit that altered the blockchain's state, which is the live record of balances, token ownership, and smart-contract data. The attack targeted transaction atomicity, a critical concept in blockchain development.

The incident occurred on September 20, 2026, when an attacker exploited a flaw in the mainnet virtual-machine layer, causing invalid changes to be recorded onchain. In response, MultiversX suspended network operations while developers worked on a patch and evaluated targeted recovery methods.

A shadow fork has been prepared for testing, which will allow engineers to reproduce real network conditions without affecting live balances. The goal is to establish whether the affected records can be corrected without reversing legitimate transactions.