# MANTRA Chain Discloses Details of $3.6 Million Exploit Blockchain network halted for 30 hours, 720 million tokens stolen. - **Source:** [INCRYPTED](https://brifing.si/source/7cd4625d-3f08-4cc1-983d-4c7d991839ba) - **Published:** 2026-08-29 - **Topic:** [Finance](https://brifing.si/c/finance) - **Original article:** - **On Brifing:** https://brifing.si/s/53e6f380-b9d7-4faf-9a33-f0e704336e3f ## Scale of the Attack On August 20, 2026, MANTRA Chain suffered a security breach resulting in the theft of 720.9 million tokens worth $3.6 million. The network was completely shut down for 30 hours and 13 minutes following the attack. The hacker exploited an unsigned-integer underflow vulnerability in the Cosmos EVM module, enabling unauthorized transfers from the network's burn address and an old genesis-era multisig wallet. ## Technical Vulnerability Details The attack stemmed from a critical flaw in Cosmos EVM's balance reconciliation mechanism. The bug allowed balance subtraction without proper authorization checks, converting failed transactions into extremely large values. By specially manipulating the staking precompile function, the attacker bypassed authorization protocols. Although identified on May 15, the patch wasn't implemented in mainnet releases until August without specific vulnerability warnings. ## Economic Consequences While no new tokens were minted, circulating supply suddenly increased by 720.9 million MANTRA. The token price stood at $0.005 during the attack. Interestingly, total supply decreased by only 0.000000000000000001 MANTRA since the stolen funds technically existed. However, as these funds were previously considered 'economically inactive,' the incident significantly impacted market dynamics. ## Hacker's Transaction Trail The attacker operated in two phases: First transferring 600 million from the network's burn address, then 120.9 million from an old multisig wallet. In total, 682.97 million tokens were sent to an exchange deposit address, while 37.96 million remain frozen in the hacker's wallet. MANTRA Chain is collaborating with law enforcement to trace the funds through blockchain forensic analysis. ## Network Response and Patch After shutting down the network, MANTRA Chain prepared the v8.4.0 update containing two critical fixes: Balance overflow errors now automatically reject transactions, and special account creations enabling such attacks are blocked. The network restarted on August 22 without rollbacks or cancellation of legitimate transactions, maintaining blockchain continuity. ## Monitoring System Gaps The initial 600 million MANTRA transfer went undetected for four hours due to incorrect assumptions about burn address capabilities. MANTRA Chain implemented enhanced monitoring protocols: Large unauthorized transfers, unsigned transactions, and activity from previously 'inactive' addresses now trigger immediate alerts. Additional security measures were applied to genesis-era wallets. ## User Impact While user wallets weren't directly compromised, the 30-hour network outage paralyzed transactions. Some exchanges suspended MANTRA deposits/withdrawals for even longer. The team emphasized that 'fund security doesn't mean users weren't harmed,' highlighting systemic risks. The full impact on token price due to eroded trust remains uncertain. ## DeFi Industry Wake-up Call This incident underscores urgent needs for heightened security standards in DeFi, which saw over 200 hacks in 2026's first half. Crypto platforms lost $3.63 billion in 2025 alone. The MANTRA case reveals specific risks in Cosmos SDK's EVM integrations, potentially driving industry-wide development of new audit protocols and security frameworks for cross-chain functionality. ## Sources covering this story - https://incrypted.com/mantra-chain-raskryla-detaly-ataky-na-36-mln/ — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._