Cosmos Labs Urges Chains to Halt as Ethereum-Compatiblity Security Incident Spreads

Cosmos Labs has issued an emergency advisory urging chains using its Cosmos EVM software to halt validator operations due to a security incident affecting users of the shared Ethereum-compatible infrastructure. The organization's security and engineering teams are 'proactively addressing' the incident, which has already resulted in two separate chain halts.

MANTRA Chain halted its Layer 1 blockchain on August 20 after detecting an exploit involving its Cosmos EVM module, while TAC detected another exploit on August 22. The TON-connected EVM network said an attacker exploited a vulnerability in the Cosmos EVM precompile layer and accessed a single account before validators stopped the blockchain.

Cosmos Labs has not yet disclosed the total amount of assets affected or provided a complete technical explanation of the latest attacks, but it is expected to release a detailed incident report once the situation is resolved. The organization's recommendation for defensive halts across potentially exposed networks is unusually aggressive, with MANTRA already forced into a 30-hour outage and TAC subsequently halting.

The shared infrastructure creates broader implications than a vulnerability isolated to one blockchain, as Cosmos EVM provides Ethereum Virtual Machine compatibility that multiple independent Cosmos SDK chains can integrate. The incidents are significant because Cosmos EVM already experienced a critical security failure earlier this year, with an attacker exploiting SagaEVM and extracting approximately $7 million.