---
id: 1761
title: "The Hidden Dangers of Crafting Your Own Regular Expressions for Input Validation"
source_domain: hackerone.com
source_url: "https://www.hackerone.com/blog/hidden-dangers-crafting-your-own-regular-expressions-input-validation"
published_at: "2024-04-03T02:40:13Z"
tags: ["denial-of-service", "web-security", "regex", "input-validation", "redos", "django"]
phying_url: "https://phying.com/item/1761"
lang: en
---

# The Hidden Dangers of Crafting Your Own Regular Expressions for Input Validation

## Summary

Hand-written regular expressions for input validation can introduce false negatives and ReDoS; this post uses Django email validation examples to show the pitfalls and safer alternatives.

## Intelligence Metadata

- **Sources:** hackerone.com
- **Published:** 2024-04-03T02:40:13Z
- **Original:** https://www.hackerone.com/blog/hidden-dangers-crafting-your-own-regular-expressions-input-validation
- **Phying News:** https://phying.com/item/1761