How to: ![✔] 6.16. Prevent evil RegEx from overloading your single thread execution
**TL;DR:** Regular Expressions, while being handy, pose a real threat to JavaScript applications at large, and the Node.js platform in particular. A user input for text to match might require an outstanding amount of CPU cycles to process. RegEx processing might be inefficient to an extent that a single request that validates 10 words can block the entire event loop for 6 seconds and set the CPU on 🔥. For that reason, prefer third-party validation packages like [validator.js](https://github.com/chriso/validator.js) instead of writing your own Regex patterns, or make use of [safe-regex](https://github.com/substack/safe-regex) to detect vulnerable regex patterns

**Otherwise:** Poorly written regexes could be susceptible to Regular Expression DoS attacks that will block the event loop completely. For example, the popular `moment` package was found vulnerable with malicious RegEx usage in November of 2017

🔗 [**Read More: Prevent malicious RegEx**](./sections/security/regex.md)