WebAssembly is a portable, low-level binary code instruction format that enables developers to write high-performance code in various languages and runs alongside JavaScript. However, it also introduces several security concerns, including module isolation issues, linear memory model vulnerabilities, JIT compilation risks, cross-site scripting attacks, and insecure content delivery. To mitigate these risks, developers can implement best practices such as sandboxing, compartmentalization, bounds checking, memory protection mechanisms, ahead-of-time compilation, applying security patches, input validation, output encoding, HTTPS encryption, and access control mechanisms. By following these measures, developers can protect users and shield their WebAssembly apps from potential security threats.