Source Code:
The source code has been audited by Peckshield and Least Authority before mainnet launch, here is the result.
Security is extremely important for a blockchain system, and Nervos Foundation started a Bug Bounty Program: www.bounty.nervos.org - It rewards the security researcher with financial compensation for a validated security report, with $25,000 max reward for a validated security report and $1 million initial rewards in total.